def test_preserves_singleton_output_partitioning(self):
# Empty DataFrame with one column and two index levels
input_expr = expressions.ConstantExpression(
pd.DataFrame(columns=["column"], index=[[], []]))
preserves_only_singleton = expressions.ComputedExpression(
'preserves_only_singleton',
# index is replaced with an entirely new one, so
# if we were partitioned by Index we're not anymore.
lambda df: df.set_index('column'),
[input_expr],
requires_partition_by=partitionings.Arbitrary(),
preserves_partition_by=partitionings.Singleton())
for partitioning in (partitionings.Singleton(), ):
self.assertEqual(
expressions.output_partitioning(preserves_only_singleton,
partitioning), partitioning,
f"Should preserve {partitioning}")
for partitioning in (partitionings.Index([0]), partitionings.Index(),
partitionings.Arbitrary()):
self.assertEqual(
expressions.output_partitioning(preserves_only_singleton,
partitioning),
partitionings.Arbitrary(),
f"Should NOT preserve {partitioning}")
def concat(
objs,
axis,
join,
ignore_index,
keys,
levels,
names,
verify_integrity,
sort,
copy):
if ignore_index:
raise NotImplementedError('concat(ignore_index)')
if levels:
raise NotImplementedError('concat(levels)')
if isinstance(objs, Mapping):
if keys is None:
keys = list(objs.keys())
objs = [objs[k] for k in keys]
else:
objs = list(objs)
if keys is None:
preserves_partitioning = partitionings.Arbitrary()
else:
# Index 0 will be a new index for keys, only partitioning by the original
# indexes (1 to N) will be preserved.
nlevels = min(o._expr.proxy().index.nlevels for o in objs)
preserves_partitioning = partitionings.Index(
[i for i in range(1, nlevels + 1)])
deferred_none = expressions.ConstantExpression(None)
exprs = [deferred_none if o is None else o._expr for o in objs]
if axis in (1, 'columns'):
required_partitioning = partitionings.Index()
elif verify_integrity:
required_partitioning = partitionings.Index()
else:
required_partitioning = partitionings.Arbitrary()
return frame_base.DeferredBase.wrap(
expressions.ComputedExpression(
'concat',
lambda *objs: pd.concat(
objs,
axis=axis,
join=join,
ignore_index=ignore_index,
keys=keys,
levels=levels,
names=names,
verify_integrity=verify_integrity), # yapf break
exprs,
requires_partition_by=required_partitioning,
preserves_partition_by=preserves_partitioning))
def __init__(self, inputs, partitioning):
self.inputs = set(inputs)
if (len(self.inputs) > 1 and
partitioning.is_subpartitioning_of(partitionings.Index())):
# We have to shuffle to co-locate, might as well partition.
self.partitioning = partitionings.Index()
elif isinstance(partitioning, partitionings.JoinIndex):
# Not an actionable partitioning, use index.
self.partitioning = partitionings.Index()
else:
self.partitioning = partitioning
self.ops = []
self.outputs = set()
def concat(
objs,
axis,
join,
ignore_index,
keys,
levels,
names,
verify_integrity,
sort,
copy):
if ignore_index:
raise NotImplementedError('concat(ignore_index)')
if levels:
raise NotImplementedError('concat(levels)')
if isinstance(objs, Mapping):
if keys is None:
keys = list(objs.keys())
objs = [objs[k] for k in keys]
else:
objs = list(objs)
deferred_none = expressions.ConstantExpression(None)
exprs = [deferred_none if o is None else o._expr for o in objs]
if axis in (1, 'columns'):
required_partitioning = partitionings.Index()
elif verify_integrity:
required_partitioning = partitionings.Index()
else:
required_partitioning = partitionings.Nothing()
return frame_base.DeferredBase.wrap(
expressions.ComputedExpression(
'concat',
lambda *objs: pd.concat(
objs,
axis=axis,
join=join,
ignore_index=ignore_index,
keys=keys,
levels=levels,
names=names,
verify_integrity=verify_integrity), # yapf break
exprs,
requires_partition_by=required_partitioning,
preserves_partition_by=partitionings.Index()))
def dot(self, other):
# We want to broadcast the right hand side to all partitions of the left.
# This is OK, as its index must be the same size as the columns set of self,
# so cannot be too large.
class AsScalar(object):
def __init__(self, value):
self.value = value
if isinstance(other, frame_base.DeferredFrame):
proxy = other._expr.proxy()
with expressions.allow_non_parallel_operations():
side = expressions.ComputedExpression(
'as_scalar',
lambda df: AsScalar(df),
[other._expr],
requires_partition_by=partitionings.Singleton())
else:
proxy = pd.DataFrame(columns=range(len(other[0])))
side = expressions.ConstantExpression(AsScalar(other))
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'dot',
lambda left, right: left @ right.value,
[self._expr, side],
requires_partition_by=partitionings.Nothing(),
preserves_partition_by=partitionings.Index(),
proxy=proxy))
def update(self, other):
self._expr = expressions.ComputedExpression(
'update',
lambda df, other: df.update(other) or df,
[self._expr, other._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Index())
def join(self, other, on, **kwargs):
if on is not None:
reindex, revert = self._cols_as_temporary_index(on)
return revert(reindex(self).join(other, **kwargs))
if isinstance(other, list):
other_is_list = True
else:
other = [other]
other_is_list = False
placeholder = object()
other_exprs = [
df._expr for df in other if isinstance(df, frame_base.DeferredFrame)]
const_others = [
placeholder if isinstance(df, frame_base.DeferredFrame) else df
for df in other]
def fill_placeholders(values):
values = iter(values)
filled = [
next(values) if df is placeholder else df for df in const_others]
if other_is_list:
return filled
else:
return filled[0]
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'join',
lambda df, *deferred_others: df.join(
fill_placeholders(deferred_others), **kwargs),
[self._expr] + other_exprs,
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Index()))
def __init__(self, inputs, partitioning):
self.inputs = set(inputs)
if len(self.inputs) > 1 and partitioning == partitionings.Nothing():
# We have to shuffle to co-locate, might as well partition.
self.partitioning = partitionings.Index()
else:
self.partitioning = partitioning
self.ops = []
self.outputs = set()
def agg(self, fn):
if not callable(fn):
raise NotImplementedError(fn)
return DeferredDataFrame(
expressions.ComputedExpression(
'agg',
lambda df: df.agg(fn), [self._expr],
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Singleton()))
def wrapper(self, *args, **kargs):
assert isinstance(self, DeferredGroupBy)
ungrouped = self._expr.args()[0]
post_agg = expressions.ComputedExpression(
name,
lambda df: func(df.groupby(level=list(range(df.index.nlevels)))),
[ungrouped],
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Singleton())
return frame_base.DeferredFrame.wrap(post_agg)
def unstack(self, *args, **kwargs):
if self._expr.proxy().index.nlevels == 1:
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'unstack',
lambda df: df.unstack(*args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Index()))
else:
raise frame_base.WontImplementError('non-deferred column values')
def merge(
self,
right,
on,
left_on,
right_on,
left_index,
right_index,
**kwargs):
self_proxy = self._expr.proxy()
right_proxy = right._expr.proxy()
# Validate with a pandas call.
_ = self_proxy.merge(
right_proxy,
on=on,
left_on=left_on,
right_on=right_on,
left_index=left_index,
right_index=right_index,
**kwargs)
if not any([on, left_on, right_on, left_index, right_index]):
on = [col for col in self_proxy.columns() if col in right_proxy.columns()]
if not left_on:
left_on = on
elif not isinstance(left_on, list):
left_on = [left_on]
if not right_on:
right_on = on
elif not isinstance(right_on, list):
right_on = [right_on]
if left_index:
indexed_left = self
else:
indexed_left = self.set_index(left_on, drop=False)
if right_index:
indexed_right = right
else:
indexed_right = right.set_index(right_on, drop=False)
merged = frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'merge',
lambda left, right: left.merge(
right, left_index=True, right_index=True, **kwargs),
[indexed_left._expr, indexed_right._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Index()))
if left_index or right_index:
return merged
else:
return merged.reset_index(drop=True)
def groupby(self, cols):
# TODO: what happens to the existing index?
# We set the columns to index as we have a notion of being partitioned by
# index, but not partitioned by an arbitrary subset of columns.
return DeferredGroupBy(
expressions.ComputedExpression(
'groupbyindex',
lambda df: df.groupby(level=list(range(df.index.nlevels))),
[self.set_index(cols)._expr],
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Singleton()))
def agg(self, fn):
if not callable(fn):
# TODO: Add support for strings in (UN)LIFTABLE_AGGREGATIONS. Test by
# running doctests for pandas.core.groupby.generic
raise NotImplementedError('GroupBy.agg currently only supports callable '
'arguments')
return DeferredDataFrame(
expressions.ComputedExpression(
'agg',
lambda df: df.agg(fn), [self._expr],
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Singleton()))
def test_preserves_index_output_partitioning(self):
# Empty DataFrame with two columns and two index levels
input_expr = expressions.ConstantExpression(
pd.DataFrame(columns=["foo", "bar"], index=[[], []]))
preserves_partial_index = expressions.ComputedExpression(
'preserves_partial_index',
# This adds an additional index level, so we'd only preserve
# partitioning on the two index levels that existed before.
lambda df: df.set_index('foo', append=True),
[input_expr],
requires_partition_by=partitionings.Arbitrary(),
preserves_partition_by=partitionings.Index([0, 1]))
for partitioning in (
partitionings.Singleton(),
partitionings.Index([0]),
partitionings.Index([1]),
partitionings.Index([0, 1]),
):
self.assertEqual(
expressions.output_partitioning(preserves_partial_index,
partitioning), partitioning,
f"Should preserve {partitioning}")
for partitioning in (partitionings.Index([0, 1, 2]),
partitionings.Index(), partitionings.Arbitrary()):
self.assertEqual(
expressions.output_partitioning(preserves_partial_index,
partitioning),
partitionings.Arbitrary(),
f"Should NOT preserve {partitioning}")
def dot(self, other):
left = self._expr
if isinstance(other, DeferredSeries):
right = expressions.ComputedExpression(
'to_dataframe',
pd.DataFrame, [other._expr],
requires_partition_by=partitionings.Nothing(),
preserves_partition_by=partitionings.Index())
right_is_series = True
elif isinstance(other, DeferredDataFrame):
right = other._expr
right_is_series = False
else:
raise frame_base.WontImplementError('non-deferred result')
dots = expressions.ComputedExpression(
'dot',
# Transpose so we can sum across rows.
(lambda left, right: pd.DataFrame(left @ right).T),
[left, right],
requires_partition_by=partitionings.Index())
with expressions.allow_non_parallel_operations(True):
sums = expressions.ComputedExpression(
'sum',
lambda dots: dots.sum(), #
[dots],
requires_partition_by=partitionings.Singleton())
if right_is_series:
result = expressions.ComputedExpression(
'extract',
lambda df: df[0], [sums],
requires_partition_by=partitionings.Singleton())
else:
result = sums
return frame_base.DeferredFrame.wrap(result)
def __init__(
self, # type: ComputedExpression
name, # type: str
func, # type: Callable[...,T]
args, # type: Iterable[Expression]
proxy=None, # type: Optional[T]
_id=None, # type: Optional[str]
requires_partition_by=partitionings.Index(
), # type: partitionings.Partitioning
preserves_partition_by=partitionings.Singleton(
), # type: partitionings.Partitioning
):
"""Initialize a computed expression.
Args:
name: The name of this expression.
func: The function that will be used to compute the value of this
expression. Should accept arguments of the types returned when
evaluating the `args` expressions.
args: The list of expressions that will be used to produce inputs to
`func`.
proxy: (Optional) a proxy object with same type as the objects that this
ComputedExpression will produce at execution time. If not provided, a
proxy will be generated using `func` and the proxies of `args`.
_id: (Optional) a string to uniquely identify this expression.
requires_partition_by: The required (common) partitioning of the args.
preserves_partition_by: The level of partitioning preserved.
"""
if (not _get_allow_non_parallel() and isinstance(
requires_partition_by, partitionings.Singleton)):
reason = requires_partition_by.reason or (
f"Encountered non-parallelizable form of {name!r}.")
raise NonParallelOperation(
f"{reason}\n"
"Consider using an allow_non_parallel_operations block if you're "
"sure you want to do this. See "
"https://s.apache.org/dataframe-non-parallel-operations for more "
"information.")
args = tuple(args)
if proxy is None:
proxy = func(*(arg.proxy() for arg in args))
super(ComputedExpression, self).__init__(name, proxy, _id)
self._func = func
self._args = args
self._requires_partition_by = requires_partition_by
self._preserves_partition_by = preserves_partition_by
def __getitem__(self, index):
if isinstance(index, tuple):
rows, cols = index
return self[rows][cols]
elif isinstance(index, list) and index and isinstance(index[0], bool):
# Aligned by numerical index.
raise NotImplementedError(type(index))
elif isinstance(index, list):
# Select rows, but behaves poorly on missing values.
raise NotImplementedError(type(index))
elif isinstance(index, slice):
args = [self._frame._expr]
func = lambda df: df.loc[index]
elif isinstance(index, frame_base.DeferredFrame):
args = [self._frame._expr, index._expr]
func = lambda df, index: df.loc[index]
elif callable(index):
def checked_callable_index(df):
computed_index = index(df)
if isinstance(computed_index, tuple):
row_index, _ = computed_index
else:
row_index = computed_index
if isinstance(row_index, list) and row_index and isinstance(
row_index[0], bool):
raise NotImplementedError(type(row_index))
elif not isinstance(row_index, (slice, pd.Series)):
raise NotImplementedError(type(row_index))
return computed_index
args = [self._frame._expr]
func = lambda df: df.loc[checked_callable_index]
else:
raise NotImplementedError(type(index))
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'loc',
func,
args,
requires_partition_by=(
partitionings.Index()
if len(args) > 1
else partitionings.Nothing()),
preserves_partition_by=partitionings.Singleton()))
def __init__(
self, # type: ComputedExpression
name, # type: str
func, # type: Callable[...,T]
args, # type: Iterable[Expression]
proxy=None, # type: Optional[T]
_id=None, # type: Optional[str]
requires_partition_by=partitionings.Index(
), # type: partitionings.Partitioning
preserves_partition_by=partitionings.Nothing(
), # type: partitionings.Partitioning
):
"""Initialize a computed expression.
Args:
name: The name of this expression.
func: The function that will be used to compute the value of this
expression. Should accept arguments of the types returned when
evaluating the `args` expressions.
args: The list of expressions that will be used to produce inputs to
`func`.
proxy: (Optional) a proxy object with same type as the objects that this
ComputedExpression will produce at execution time. If not provided, a
proxy will be generated using `func` and the proxies of `args`.
_id: (Optional) a string to uniquely identify this expression.
requires_partition_by_index: Whether this expression requires its
argument(s) to be partitioned by index.
preserves_partition_by_index: Whether the result of this expression will
be partitioned by index whenever all of its inputs are partitioned by
index.
"""
if (not _get_allow_non_parallel()
and requires_partition_by == partitionings.Singleton()):
raise NonParallelOperation(
"Using non-parallel form of %s "
"outside of allow_non_parallel_operations block." % name)
args = tuple(args)
if proxy is None:
proxy = func(*(arg.proxy() for arg in args))
super(ComputedExpression, self).__init__(name, proxy, _id)
self._func = func
self._args = args
self._requires_partition_by = requires_partition_by
self._preserves_partition_by = preserves_partition_by
def evaluate(self, expr):
import pandas as pd
import collections
def is_scalar(expr):
return not isinstance(expr.proxy(), pd.core.generic.NDFrame)
if expr not in self._bindings:
if is_scalar(expr) or not expr.args():
result = super(PartitioningSession, self).evaluate(expr)
else:
scaler_args = [arg for arg in expr.args() if is_scalar(arg)]
def evaluate_with(input_partitioning):
parts = collections.defaultdict(lambda: Session(
{arg: self.evaluate(arg)
for arg in scaler_args}))
for arg in expr.args():
if not is_scalar(arg):
input = self.evaluate(arg)
for key, part in input_partitioning.test_partition_fn(
input):
parts[key]._bindings[arg] = part
if not parts:
parts[None] # Create at least one entry.
results = []
for session in parts.values():
if any(
len(session.lookup(arg))
for arg in expr.args() if not is_scalar(arg)):
results.append(session.evaluate(expr))
expected_output_partitioning = expr.preserves_partition_by(
) if input_partitioning.is_subpartitioning_of(
expr.preserves_partition_by()) else input_partitioning
if not expected_output_partitioning.check(results):
raise AssertionError(
f"""Expression does not preserve partitioning!
Expression: {expr}
Requires: {expr.requires_partition_by()}
Preserves: {expr.preserves_partition_by()}
Input partitioning: {input_partitioning}
Expected output partitioning: {expected_output_partitioning}
""")
if results:
return pd.concat(results)
else:
# Choose any single session.
return next(iter(parts.values())).evaluate(expr)
# Store random state so it can be re-used for each execution, in case
# the expression is part of a test that relies on the random seed.
random_state = random.getstate()
for input_partitioning in set([
expr.requires_partition_by(),
partitionings.Nothing(),
partitionings.Index(),
partitionings.Singleton()
]):
if not input_partitioning.is_subpartitioning_of(
expr.requires_partition_by()):
continue
random.setstate(random_state)
# TODO(BEAM-11324): Consider verifying result is always the same
result = evaluate_with(input_partitioning)
self._bindings[expr] = result
return self._bindings[expr]
def wrapper(*args, **kwargs):
for key, values in (): #restrictions.items():
if key in kwargs:
value = kwargs[key]
else:
try:
ix = _getargspec(func).args.index(key)
except ValueError:
# TODO: fix for delegation?
continue
if len(args) <= ix:
continue
value = args[ix]
if not isinstance(values, list):
values = [values]
if value not in values:
raise NotImplementedError('%s=%s not supported for %s' %
(key, value, name))
deferred_arg_indices = []
deferred_arg_exprs = []
constant_args = [None] * len(args)
for ix, arg in enumerate(args):
if isinstance(arg, DeferredBase):
deferred_arg_indices.append(ix)
deferred_arg_exprs.append(arg._expr)
elif isinstance(arg, pd.core.generic.NDFrame):
deferred_arg_indices.append(ix)
deferred_arg_exprs.append(
expressions.ConstantExpression(arg, arg[0:0]))
else:
constant_args[ix] = arg
if inplace:
actual_func = copy_and_mutate(func)
else:
actual_func = func
def apply(*actual_args):
full_args = list(constant_args)
for ix, arg in zip(deferred_arg_indices, actual_args):
full_args[ix] = arg
return actual_func(*full_args, **kwargs)
if any(
isinstance(arg.proxy(), pd.core.generic.NDFrame)
for arg in deferred_arg_exprs
) and not requires_partition_by.is_subpartitioning_of(
partitionings.Index()):
# Implicit join on index.
actual_requires_partition_by = partitionings.Index()
else:
actual_requires_partition_by = requires_partition_by
result_expr = expressions.ComputedExpression(
name,
apply,
deferred_arg_exprs,
requires_partition_by=actual_requires_partition_by,
preserves_partition_by=preserves_partition_by)
if inplace:
args[0]._expr = result_expr
else:
return DeferredFrame.wrap(result_expr)
def evaluate(self, expr):
import pandas as pd
import collections
def is_scalar(expr):
return not isinstance(expr.proxy(), pd.core.generic.NDFrame)
if expr not in self._bindings:
if is_scalar(expr) or not expr.args():
result = super(PartitioningSession, self).evaluate(expr)
else:
scaler_args = [arg for arg in expr.args() if is_scalar(arg)]
def evaluate_with(input_partitioning):
parts = collections.defaultdict(lambda: Session(
{arg: self.evaluate(arg)
for arg in scaler_args}))
for arg in expr.args():
if not is_scalar(arg):
input = self.evaluate(arg)
for key, part in input_partitioning.test_partition_fn(
input):
parts[key]._bindings[arg] = part
if not parts:
parts[None] # Create at least one entry.
results = []
for session in parts.values():
if any(
len(session.lookup(arg))
for arg in expr.args() if not is_scalar(arg)):
results.append(session.evaluate(expr))
expected_output_partitioning = output_partitioning(
expr, input_partitioning)
if not expected_output_partitioning.check(results):
raise AssertionError(
f"""Expression does not preserve partitioning!
Expression: {expr}
Requires: {expr.requires_partition_by()}
Preserves: {expr.preserves_partition_by()}
Input partitioning: {input_partitioning}
Expected output partitioning: {expected_output_partitioning}
""")
if results:
return pd.concat(results)
else:
# Choose any single session.
return next(iter(parts.values())).evaluate(expr)
# Store random state so it can be re-used for each execution, in case
# the expression is part of a test that relies on the random seed.
random_state = random.getstate()
result = None
# Run with all supported partitionings s.t. the smallest subpartitioning
# is used last. This way the final result is computed with the most
# challenging partitioning. Avoids heisenbugs where sometimes the result
# is computed trivially with Singleton partitioning and passes.
for input_partitioning in sorted(
set([
expr.requires_partition_by(),
partitionings.Arbitrary(),
partitionings.Index(),
partitionings.Singleton()
])):
if not expr.requires_partition_by().is_subpartitioning_of(
input_partitioning):
continue
random.setstate(random_state)
result = evaluate_with(input_partitioning)
assert result is not None
self._bindings[expr] = result
return self._bindings[expr]
def preserves_partition_by(self):
return partitionings.Index()
class DeferredDataFrame(frame_base.DeferredFrame):
@property
def T(self):
return self.transpose()
def groupby(self, cols):
# TODO: what happens to the existing index?
# We set the columns to index as we have a notion of being partitioned by
# index, but not partitioned by an arbitrary subset of columns.
return DeferredGroupBy(
expressions.ComputedExpression(
'groupbyindex',
lambda df: df.groupby(level=list(range(df.index.nlevels))),
[self.set_index(cols)._expr],
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Singleton()))
def __getattr__(self, name):
# Column attribute access.
if name in self._expr.proxy().columns:
return self[name]
else:
return object.__getattribute__(self, name)
def __getitem__(self, key):
if key in self._expr.proxy().columns:
return self._elementwise(lambda df: df[key], 'get_column')
else:
raise NotImplementedError(key)
def __setitem__(self, key, value):
if isinstance(key, str):
# yapf: disable
return self._elementwise(
lambda df, key, value: df.__setitem__(key, value),
'set_column',
(key, value),
inplace=True)
else:
raise NotImplementedError(key)
def set_index(self, keys, **kwargs):
if isinstance(keys, str):
keys = [keys]
if not set(keys).issubset(self._expr.proxy().columns):
raise NotImplementedError(keys)
return self._elementwise(
lambda df: df.set_index(keys, **kwargs),
'set_index',
inplace=kwargs.get('inplace', False))
def at(self, *args, **kwargs):
raise NotImplementedError()
@property
def loc(self):
return _DeferredLoc(self)
def aggregate(self, func, axis=0, *args, **kwargs):
if axis is None:
# Aggregate across all elements by first aggregating across columns,
# then across rows.
return self.agg(func, *args, **dict(kwargs, axis=1)).agg(
func, *args, **dict(kwargs, axis=0))
elif axis in (1, 'columns'):
# This is an easy elementwise aggregation.
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'aggregate',
lambda df: df.agg(func, axis=1, *args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Nothing()))
elif len(self._expr.proxy().columns) == 0 or args or kwargs:
# For these corner cases, just colocate everything.
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'aggregate',
lambda df: df.agg(func, *args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Singleton()))
else:
# In the general case, compute the aggregation of each column separately,
# then recombine.
if not isinstance(func, dict):
col_names = list(self._expr.proxy().columns)
func = {col: func for col in col_names}
else:
col_names = list(func.keys())
aggregated_cols = []
for col in col_names:
funcs = func[col]
if not isinstance(funcs, list):
funcs = [funcs]
aggregated_cols.append(self[col].agg(funcs, *args, **kwargs))
# The final shape is different depending on whether any of the columns
# were aggregated by a list of aggregators.
with expressions.allow_non_parallel_operations():
if any(isinstance(funcs, list) for funcs in func.values()):
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'join_aggregate',
lambda *cols: pd.DataFrame(
{col: value for col, value in zip(col_names, cols)}),
[col._expr for col in aggregated_cols],
requires_partition_by=partitionings.Singleton()))
else:
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'join_aggregate',
lambda *cols: pd.Series(
{col: value[0] for col, value in zip(col_names, cols)}),
[col._expr for col in aggregated_cols],
requires_partition_by=partitionings.Singleton(),
proxy=self._expr.proxy().agg(func, *args, **kwargs)))
agg = aggregate
applymap = frame_base._elementwise_method('applymap')
memory_usage = frame_base.wont_implement_method('non-deferred value')
all = frame_base._agg_method('all')
any = frame_base._agg_method('any')
cummax = cummin = cumsum = cumprod = frame_base.wont_implement_method(
'order-sensitive')
diff = frame_base.wont_implement_method('order-sensitive')
max = frame_base._agg_method('max')
min = frame_base._agg_method('min')
def mode(self, axis=0, *args, **kwargs):
if axis == 1 or axis == 'columns':
raise frame_base.WontImplementError('non-deferred column values')
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'mode',
lambda df: df.mode(*args, **kwargs),
[self._expr],
#TODO(robertwb): Approximate?
requires_partition_by=partitionings.Singleton(),
preserves_partition_by=partitionings.Singleton()))
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def dropna(self, axis, **kwargs):
# TODO(robertwb): This is a common pattern. Generalize?
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Singleton()
else:
requires_partition_by = partitionings.Nothing()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'dropna',
lambda df: df.dropna(axis=axis, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
items = itertuples = iterrows = iteritems = frame_base.wont_implement_method(
'non-lazy')
isna = frame_base._elementwise_method('isna')
notnull = notna = frame_base._elementwise_method('notna')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def fillna(self, value, method, axis, **kwargs):
if method is not None and axis in (0, 'index'):
raise frame_base.WontImplementError('order-sensitive')
if isinstance(value, frame_base.DeferredBase):
value_expr = value._expr
else:
value_expr = expressions.ConstantExpression(value)
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'fillna',
lambda df, value: df.fillna(
value, method=method, axis=axis, **kwargs),
[self._expr, value_expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Nothing()))
prod = product = frame_base._agg_method('prod')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def quantile(self, axis, **kwargs):
if axis == 1 or axis == 'columns':
raise frame_base.WontImplementError('non-deferred column values')
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'quantile',
lambda df: df.quantile(axis=axis, **kwargs),
[self._expr],
#TODO(robertwb): Approximate quantiles?
requires_partition_by=partitionings.Singleton(),
preserves_partition_by=partitionings.Singleton()))
query = frame_base._elementwise_method('query')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def replace(self, limit, **kwargs):
if limit is None:
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'replace',
lambda df: df.replace(limit=limit, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def reset_index(self, level, **kwargs):
if level is not None and not isinstance(level, (tuple, list)):
level = [level]
if level is None or len(level) == len(self._expr.proxy().index.levels):
# TODO: Could do distributed re-index with offsets.
requires_partition_by = partitionings.Singleton()
else:
requires_partition_by = partitionings.Nothing()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'reset_index',
lambda df: df.reset_index(level=level, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
round = frame_base._elementwise_method('round')
select_dtypes = frame_base._elementwise_method('select_dtypes')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def shift(self, axis, **kwargs):
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'shift',
lambda df: df.shift(axis=axis, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
@property
def shape(self):
raise frame_base.WontImplementError('scalar value')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def sort_values(self, axis, **kwargs):
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'sort_values',
lambda df: df.sort_values(axis=axis, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
stack = frame_base._elementwise_method('stack')
sum = frame_base._agg_method('sum')
take = frame_base.wont_implement_method('deprecated')
to_records = to_dict = to_numpy = to_string = (
frame_base.wont_implement_method('non-deferred value'))
to_sparse = to_string # frame_base._elementwise_method('to_sparse')
transform = frame_base._elementwise_method(
'transform', restrictions={'axis': 0})
def transpose(self, *args, **kwargs):
raise frame_base.WontImplementError('non-deferred column values')
def unstack(self, *args, **kwargs):
if self._expr.proxy().index.nlevels == 1:
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'unstack',
lambda df: df.unstack(*args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Index()))
else:
raise frame_base.WontImplementError('non-deferred column values')
update = frame_base._proxy_method(
'update',
inplace=True,
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Index())
class DeferredDataFrame(frame_base.DeferredFrame):
@property
def T(self):
return self.transpose()
@property
def columns(self):
return self._expr.proxy().columns
def groupby(self, by):
# TODO: what happens to the existing index?
# We set the columns to index as we have a notion of being partitioned by
# index, but not partitioned by an arbitrary subset of columns.
return DeferredGroupBy(
expressions.ComputedExpression(
'groupbyindex',
lambda df: df.groupby(level=list(range(df.index.nlevels))),
[self.set_index(by)._expr],
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Singleton()))
def __getattr__(self, name):
# Column attribute access.
if name in self._expr.proxy().columns:
return self[name]
else:
return object.__getattribute__(self, name)
def __getitem__(self, key):
# TODO: Replicate pd.DataFrame.__getitem__ logic
if isinstance(key, frame_base.DeferredBase):
# Fail early if key is a DeferredBase as it interacts surprisingly with
# key in self._expr.proxy().columns
raise NotImplementedError(
"Indexing with a deferred frame is not yet supported. Consider "
"using df.loc[...]")
if (isinstance(key, list) and
all(key_column in self._expr.proxy().columns
for key_column in key)) or key in self._expr.proxy().columns:
return self._elementwise(lambda df: df[key], 'get_column')
else:
raise NotImplementedError(key)
def __contains__(self, key):
# Checks if proxy has the given column
return self._expr.proxy().__contains__(key)
def __setitem__(self, key, value):
if isinstance(key, str):
# yapf: disable
return self._elementwise(
lambda df, key, value: df.__setitem__(key, value),
'set_column',
(key, value),
inplace=True)
else:
raise NotImplementedError(key)
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def set_index(self, keys, **kwargs):
if isinstance(keys, str):
keys = [keys]
if not set(keys).issubset(self._expr.proxy().columns):
raise NotImplementedError(keys)
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'set_index',
lambda df: df.set_index(keys, **kwargs),
[self._expr],
requires_partition_by=partitionings.Nothing(),
preserves_partition_by=partitionings.Nothing()))
at = frame_base.not_implemented_method('at')
@property
def loc(self):
return _DeferredLoc(self)
_get_index = _set_index = frame_base.not_implemented_method('index')
index = property(_get_index, _set_index)
@property
def axes(self):
return (self.index, self.columns)
apply = frame_base.not_implemented_method('apply')
explode = frame_base.not_implemented_method('explode')
isin = frame_base.not_implemented_method('isin')
assign = frame_base.not_implemented_method('assign')
append = frame_base.not_implemented_method('append')
combine = frame_base.not_implemented_method('combine')
combine_first = frame_base.not_implemented_method('combine_first')
cov = frame_base.not_implemented_method('cov')
corr = frame_base.not_implemented_method('corr')
count = frame_base.not_implemented_method('count')
drop = frame_base.not_implemented_method('drop')
eval = frame_base.not_implemented_method('eval')
reindex = frame_base.not_implemented_method('reindex')
melt = frame_base.not_implemented_method('melt')
pivot = frame_base.not_implemented_method('pivot')
pivot_table = frame_base.not_implemented_method('pivot_table')
def aggregate(self, func, axis=0, *args, **kwargs):
if axis is None:
# Aggregate across all elements by first aggregating across columns,
# then across rows.
return self.agg(func, *args, **dict(kwargs, axis=1)).agg(
func, *args, **dict(kwargs, axis=0))
elif axis in (1, 'columns'):
# This is an easy elementwise aggregation.
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'aggregate',
lambda df: df.agg(func, axis=1, *args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Nothing()))
elif len(self._expr.proxy().columns) == 0 or args or kwargs:
# For these corner cases, just colocate everything.
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'aggregate',
lambda df: df.agg(func, *args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Singleton()))
else:
# In the general case, compute the aggregation of each column separately,
# then recombine.
if not isinstance(func, dict):
col_names = list(self._expr.proxy().columns)
func = {col: func for col in col_names}
else:
col_names = list(func.keys())
aggregated_cols = []
for col in col_names:
funcs = func[col]
if not isinstance(funcs, list):
funcs = [funcs]
aggregated_cols.append(self[col].agg(funcs, *args, **kwargs))
# The final shape is different depending on whether any of the columns
# were aggregated by a list of aggregators.
with expressions.allow_non_parallel_operations():
if any(isinstance(funcs, list) for funcs in func.values()):
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'join_aggregate',
lambda *cols: pd.DataFrame(
{col: value for col, value in zip(col_names, cols)}),
[col._expr for col in aggregated_cols],
requires_partition_by=partitionings.Singleton()))
else:
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'join_aggregate',
lambda *cols: pd.Series(
{col: value[0] for col, value in zip(col_names, cols)}),
[col._expr for col in aggregated_cols],
requires_partition_by=partitionings.Singleton(),
proxy=self._expr.proxy().agg(func, *args, **kwargs)))
agg = aggregate
applymap = frame_base._elementwise_method('applymap')
memory_usage = frame_base.wont_implement_method('non-deferred value')
info = frame_base.wont_implement_method('non-deferred value')
all = frame_base._agg_method('all')
any = frame_base._agg_method('any')
cummax = cummin = cumsum = cumprod = frame_base.wont_implement_method(
'order-sensitive')
diff = frame_base.wont_implement_method('order-sensitive')
def dot(self, other):
# We want to broadcast the right hand side to all partitions of the left.
# This is OK, as its index must be the same size as the columns set of self,
# so cannot be too large.
class AsScalar(object):
def __init__(self, value):
self.value = value
if isinstance(other, frame_base.DeferredFrame):
proxy = other._expr.proxy()
with expressions.allow_non_parallel_operations():
side = expressions.ComputedExpression(
'as_scalar',
lambda df: AsScalar(df),
[other._expr],
requires_partition_by=partitionings.Singleton())
else:
proxy = pd.DataFrame(columns=range(len(other[0])))
side = expressions.ConstantExpression(AsScalar(other))
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'dot',
lambda left, right: left @ right.value,
[self._expr, side],
requires_partition_by=partitionings.Nothing(),
preserves_partition_by=partitionings.Index(),
proxy=proxy))
__matmul__ = dot
head = tail = frame_base.wont_implement_method('order-sensitive')
max = frame_base._agg_method('max')
min = frame_base._agg_method('min')
def mode(self, axis=0, *args, **kwargs):
if axis == 1 or axis == 'columns':
# Number of columns is max(number mode values for each row), so we can't
# determine how many there will be before looking at the data.
raise frame_base.WontImplementError('non-deferred column values')
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'mode',
lambda df: df.mode(*args, **kwargs),
[self._expr],
#TODO(robertwb): Approximate?
requires_partition_by=partitionings.Singleton(),
preserves_partition_by=partitionings.Singleton()))
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def dropna(self, axis, **kwargs):
# TODO(robertwb): This is a common pattern. Generalize?
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Singleton()
else:
requires_partition_by = partitionings.Nothing()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'dropna',
lambda df: df.dropna(axis=axis, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def fillna(self, value, method, axis, **kwargs):
if method is not None and axis in (0, 'index'):
raise frame_base.WontImplementError('order-sensitive')
if isinstance(value, frame_base.DeferredBase):
value_expr = value._expr
else:
value_expr = expressions.ConstantExpression(value)
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'fillna',
lambda df, value: df.fillna(
value, method=method, axis=axis, **kwargs),
[self._expr, value_expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Nothing()))
isna = frame_base._elementwise_method('isna')
notnull = notna = frame_base._elementwise_method('notna')
items = itertuples = iterrows = iteritems = frame_base.wont_implement_method(
'non-lazy')
def _cols_as_temporary_index(self, cols, suffix=''):
original_index_names = list(self._expr.proxy().index.names)
new_index_names = [
'__apache_beam_temp_%d_%s' % (ix, suffix)
for (ix, _) in enumerate(original_index_names)]
def reindex(df):
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'reindex',
lambda df:
df.rename_axis(index=new_index_names, copy=False)
.reset_index().set_index(cols),
[df._expr],
preserves_partition_by=partitionings.Nothing(),
requires_partition_by=partitionings.Nothing()))
def revert(df):
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'join_restoreindex',
lambda df:
df.reset_index().set_index(new_index_names)
.rename_axis(index=original_index_names, copy=False),
[df._expr],
preserves_partition_by=partitionings.Nothing(),
requires_partition_by=partitionings.Nothing()))
return reindex, revert
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def join(self, other, on, **kwargs):
if on is not None:
reindex, revert = self._cols_as_temporary_index(on)
return revert(reindex(self).join(other, **kwargs))
if isinstance(other, list):
other_is_list = True
else:
other = [other]
other_is_list = False
placeholder = object()
other_exprs = [
df._expr for df in other if isinstance(df, frame_base.DeferredFrame)]
const_others = [
placeholder if isinstance(df, frame_base.DeferredFrame) else df
for df in other]
def fill_placeholders(values):
values = iter(values)
filled = [
next(values) if df is placeholder else df for df in const_others]
if other_is_list:
return filled
else:
return filled[0]
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'join',
lambda df, *deferred_others: df.join(
fill_placeholders(deferred_others), **kwargs),
[self._expr] + other_exprs,
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Index()))
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def merge(
self,
right,
on,
left_on,
right_on,
left_index,
right_index,
**kwargs):
self_proxy = self._expr.proxy()
right_proxy = right._expr.proxy()
# Validate with a pandas call.
_ = self_proxy.merge(
right_proxy,
on=on,
left_on=left_on,
right_on=right_on,
left_index=left_index,
right_index=right_index,
**kwargs)
if not any([on, left_on, right_on, left_index, right_index]):
on = [col for col in self_proxy.columns() if col in right_proxy.columns()]
if not left_on:
left_on = on
elif not isinstance(left_on, list):
left_on = [left_on]
if not right_on:
right_on = on
elif not isinstance(right_on, list):
right_on = [right_on]
if left_index:
indexed_left = self
else:
indexed_left = self.set_index(left_on, drop=False)
if right_index:
indexed_right = right
else:
indexed_right = right.set_index(right_on, drop=False)
merged = frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'merge',
lambda left, right: left.merge(
right, left_index=True, right_index=True, **kwargs),
[indexed_left._expr, indexed_right._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Index()))
if left_index or right_index:
return merged
else:
return merged.reset_index(drop=True)
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def nlargest(self, keep, **kwargs):
if keep == 'any':
keep = 'first'
elif keep != 'all':
raise frame_base.WontImplementError('order-sensitive')
kwargs['keep'] = keep
per_partition = expressions.ComputedExpression(
'nlargest-per-partition',
lambda df: df.nlargest(**kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Nothing())
with expressions.allow_non_parallel_operations(True):
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'nlargest',
lambda df: df.nlargest(**kwargs),
[per_partition],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Singleton()))
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def nsmallest(self, keep, **kwargs):
if keep == 'any':
keep = 'first'
elif keep != 'all':
raise frame_base.WontImplementError('order-sensitive')
kwargs['keep'] = keep
per_partition = expressions.ComputedExpression(
'nsmallest-per-partition',
lambda df: df.nsmallest(**kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Nothing())
with expressions.allow_non_parallel_operations(True):
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'nsmallest',
lambda df: df.nsmallest(**kwargs),
[per_partition],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Singleton()))
@frame_base.args_to_kwargs(pd.DataFrame)
def nunique(self, **kwargs):
if kwargs.get('axis', None) in (1, 'columns'):
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'nunique',
lambda df: df.nunique(**kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
prod = product = frame_base._agg_method('prod')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def quantile(self, axis, **kwargs):
if axis == 1 or axis == 'columns':
raise frame_base.WontImplementError('non-deferred column values')
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'quantile',
lambda df: df.quantile(axis=axis, **kwargs),
[self._expr],
#TODO(robertwb): Approximate quantiles?
requires_partition_by=partitionings.Singleton(),
preserves_partition_by=partitionings.Singleton()))
query = frame_base._elementwise_method('query')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.maybe_inplace
def rename(self, **kwargs):
rename_index = (
'index' in kwargs
or kwargs.get('axis', None) in (0, 'index')
or ('columns' not in kwargs and 'axis' not in kwargs))
if rename_index:
# Technically, it's still partitioned by index, but it's no longer
# partitioned by the hash of the index.
preserves_partition_by = partitionings.Nothing()
else:
preserves_partition_by = partitionings.Singleton()
if kwargs.get('errors', None) == 'raise' and rename_index:
# Renaming index with checking.
requires_partition_by = partitionings.Singleton()
proxy = self._expr.proxy()
else:
requires_partition_by = partitionings.Nothing()
proxy = None
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'rename',
lambda df: df.rename(**kwargs),
[self._expr],
proxy=proxy,
preserves_partition_by=preserves_partition_by,
requires_partition_by=requires_partition_by))
rename_axis = frame_base._elementwise_method('rename_axis')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def replace(self, limit, **kwargs):
if limit is None:
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'replace',
lambda df: df.replace(limit=limit, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def reset_index(self, level=None, **kwargs):
if level is not None and not isinstance(level, (tuple, list)):
level = [level]
if level is None or len(level) == len(self._expr.proxy().index.levels):
# TODO: Could do distributed re-index with offsets.
requires_partition_by = partitionings.Singleton()
else:
requires_partition_by = partitionings.Nothing()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'reset_index',
lambda df: df.reset_index(level=level, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
round = frame_base._elementwise_method('round')
select_dtypes = frame_base._elementwise_method('select_dtypes')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
def shift(self, axis, **kwargs):
if 'freq' in kwargs:
raise frame_base.WontImplementError('data-dependent')
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'shift',
lambda df: df.shift(axis=axis, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
@property
def shape(self):
raise frame_base.WontImplementError('scalar value')
@frame_base.args_to_kwargs(pd.DataFrame)
@frame_base.populate_defaults(pd.DataFrame)
@frame_base.maybe_inplace
def sort_values(self, axis, **kwargs):
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'sort_values',
lambda df: df.sort_values(axis=axis, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
stack = frame_base._elementwise_method('stack')
sum = frame_base._agg_method('sum')
take = frame_base.wont_implement_method('deprecated')
to_records = to_dict = to_numpy = to_string = (
frame_base.wont_implement_method('non-deferred value'))
to_sparse = to_string # frame_base._elementwise_method('to_sparse')
transform = frame_base._elementwise_method(
'transform', restrictions={'axis': 0})
transpose = frame_base.wont_implement_method('non-deferred column values')
def unstack(self, *args, **kwargs):
if self._expr.proxy().index.nlevels == 1:
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'unstack',
lambda df: df.unstack(*args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Index()))
else:
raise frame_base.WontImplementError('non-deferred column values')
update = frame_base._proxy_method(
'update',
inplace=True,
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Index())
def wrapper(*args, **kwargs):
for key, values in restrictions.items():
if key in kwargs:
value = kwargs[key]
else:
try:
ix = _getargspec(func).args.index(key)
except ValueError:
# TODO: fix for delegation?
continue
if len(args) <= ix:
continue
value = args[ix]
if callable(values):
check = values
elif isinstance(values, list):
check = lambda x, values=values: x in values
else:
check = lambda x, value=value: x == value
if not check(value):
raise NotImplementedError('%s=%s not supported for %s' %
(key, value, name))
deferred_arg_indices = []
deferred_arg_exprs = []
constant_args = [None] * len(args)
from apache_beam.dataframe.frames import _DeferredIndex
for ix, arg in enumerate(args):
if isinstance(arg, DeferredBase):
deferred_arg_indices.append(ix)
deferred_arg_exprs.append(arg._expr)
elif isinstance(arg, _DeferredIndex):
# TODO(robertwb): Consider letting indices pass through as indices.
# This would require updating the partitioning code, as indices don't
# have indices.
deferred_arg_indices.append(ix)
deferred_arg_exprs.append(
expressions.ComputedExpression(
'index_as_series',
lambda ix: ix.index.to_series(), # yapf break
[arg._frame._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=partitionings.Nothing()))
elif isinstance(arg, pd.core.generic.NDFrame):
deferred_arg_indices.append(ix)
deferred_arg_exprs.append(
expressions.ConstantExpression(arg, arg[0:0]))
else:
constant_args[ix] = arg
deferred_kwarg_keys = []
deferred_kwarg_exprs = []
constant_kwargs = {key: None for key in kwargs}
for key, arg in kwargs.items():
if isinstance(arg, DeferredBase):
deferred_kwarg_keys.append(key)
deferred_kwarg_exprs.append(arg._expr)
elif isinstance(arg, pd.core.generic.NDFrame):
deferred_kwarg_keys.append(key)
deferred_kwarg_exprs.append(
expressions.ConstantExpression(arg, arg[0:0]))
else:
constant_kwargs[key] = arg
deferred_exprs = deferred_arg_exprs + deferred_kwarg_exprs
if inplace:
actual_func = copy_and_mutate(func)
else:
actual_func = func
def apply(*actual_args):
actual_args, actual_kwargs = (
actual_args[:len(deferred_arg_exprs)],
actual_args[len(deferred_arg_exprs):])
full_args = list(constant_args)
for ix, arg in zip(deferred_arg_indices, actual_args):
full_args[ix] = arg
full_kwargs = dict(constant_kwargs)
for key, arg in zip(deferred_kwarg_keys, actual_kwargs):
full_kwargs[key] = arg
return actual_func(*full_args, **full_kwargs)
if (not requires_partition_by.is_subpartitioning_of(
partitionings.Index()) and sum(
isinstance(arg.proxy(), pd.core.generic.NDFrame)
for arg in deferred_exprs) > 1):
# Implicit join on index if there is more than one indexed input.
actual_requires_partition_by = partitionings.Index()
else:
actual_requires_partition_by = requires_partition_by
result_expr = expressions.ComputedExpression(
name,
apply,
deferred_exprs,
requires_partition_by=actual_requires_partition_by,
preserves_partition_by=preserves_partition_by)
if inplace:
args[0]._expr = result_expr
else:
return DeferredFrame.wrap(result_expr)
class DeferredDataFrame(frame_base.DeferredFrame):
@property
def T(self):
return self.transpose()
def groupby(self, cols):
# TODO: what happens to the existing index?
# We set the columns to index as we have a notion of being partitioned by
# index, but not partitioned by an arbitrary subset of columns.
return DeferredGroupBy(
expressions.ComputedExpression(
'groupbyindex',
lambda df: df.groupby(level=list(range(df.index.nlevels))),
[self.set_index(cols)._expr],
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Singleton()))
def __getattr__(self, name):
# Column attribute access.
if name in self._expr.proxy().columns:
return self[name]
else:
return object.__getattribute__(self, name)
def __getitem__(self, key):
if key in self._expr.proxy().columns:
return self._elementwise(lambda df: df[key], 'get_column')
else:
raise NotImplementedError(key)
def __setitem__(self, key, value):
if isinstance(key, str):
# yapf: disable
return self._elementwise(
lambda df, key, value: df.__setitem__(key, value),
'set_column',
(key, value),
inplace=True)
else:
raise NotImplementedError(key)
def set_index(self, keys, **kwargs):
if isinstance(keys, str):
keys = [keys]
if not set(keys).issubset(self._expr.proxy().columns):
raise NotImplementedError(keys)
return self._elementwise(
lambda df: df.set_index(keys, **kwargs),
'set_index',
inplace=kwargs.get('inplace', False))
def at(self, *args, **kwargs):
raise NotImplementedError()
@property
def loc(self):
return _DeferredLoc(self)
def aggregate(self, *args, **kwargs):
if 'axis' in kwargs and kwargs['axis'] is None:
return self.agg(*args, **dict(kwargs, axis=1)).agg(
*args, **dict(kwargs, axis=0))
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'aggregate',
lambda df: df.agg(*args, **kwargs),
[self._expr],
# TODO(robertwb): Sub-aggregate when possible.
requires_partition_by=partitionings.Singleton()))
agg = aggregate
applymap = frame_base._elementwise_method('applymap')
memory_usage = frame_base.wont_implement_method('non-deferred value')
all = frame_base._associative_agg_method('all')
any = frame_base._associative_agg_method('any')
cummax = cummin = cumsum = cumprod = frame_base.wont_implement_method(
'order-sensitive')
diff = frame_base.wont_implement_method('order-sensitive')
max = frame_base._associative_agg_method('max')
min = frame_base._associative_agg_method('min')
mode = frame_base._agg_method('mode')
def dropna(
self,
axis=0,
how='any',
thresh=None,
subset=None,
inplace=False,
*args,
**kwargs):
# TODO(robertwb): This is a common pattern. Generalize?
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Singleton()
else:
requires_partition_by = partitionings.Nothing()
result = frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'dropna',
lambda df: df.dropna(
axis, how, thresh, subset, False, *args, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
if inplace:
self._expr = result._expr
else:
return result
items = itertuples = iterrows = iteritems = frame_base.wont_implement_method(
'non-lazy')
isna = frame_base._elementwise_method('isna')
notnull = notna = frame_base._elementwise_method('notna')
prod = product = frame_base._associative_agg_method('prod')
def quantile(self, q=0.5, axis=0, *args, **kwargs):
if axis != 0:
raise frame_base.WontImplementError('non-deferred column values')
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'quantile',
lambda df: df.quantile(q, axis, *args, **kwargs),
[self._expr],
#TODO(robertwb): Approximate quantiles?
requires_partition_by=partitionings.Singleton(),
preserves_partition_by=partitionings.Singleton()))
query = frame_base._elementwise_method('query')
def replace(self, to_replace=None,
value=None,
inplace=False,
limit=None, *args, **kwargs):
if limit is None:
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
result = frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'replace',
lambda df: df.replace(
to_replace, value, False, limit, *args, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
if inplace:
self._expr = result._expr
else:
return result
def reset_index(self, level=None, drop=False, inplace=False, *args, **kwargs):
if level is not None and not isinstance(level, (tuple, list)):
level = [level]
if level is None or len(level) == len(self._expr.proxy().index.levels):
# TODO: Could do distributed re-index with offsets.
requires_partition_by = partitionings.Singleton()
else:
requires_partition_by = partitionings.Nothing()
result = frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'reset_index',
lambda df: df.reset_index(level, drop, False, *args, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
if inplace:
self._expr = result._expr
else:
return result
round = frame_base._elementwise_method('round')
select_dtypes = frame_base._elementwise_method('select_dtypes')
def shift(self, periods=1, freq=None, axis=0, *args, **kwargs):
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'shift',
lambda df: df.shift(periods, freq, axis, *args, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
@property
def shape(self):
raise frame_base.WontImplementError('scalar value')
def sort_values(
self, by, axis=0, ascending=True, inplace=False, *args, **kwargs):
if axis == 1 or axis == 'columns':
requires_partition_by = partitionings.Nothing()
else:
requires_partition_by = partitionings.Singleton()
result = frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'sort_values',
lambda df: df.sort_values(
by, axis, ascending, False, *args, **kwargs),
[self._expr],
preserves_partition_by=partitionings.Singleton(),
requires_partition_by=requires_partition_by))
if inplace:
self._expr = result._expr
else:
return result
stack = frame_base._elementwise_method('stack')
sum = frame_base._associative_agg_method('sum')
to_records = to_dict = to_numpy = to_string = (
frame_base.wont_implement_method('non-deferred value'))
to_sparse = to_string # frame_base._elementwise_method('to_sparse')
transform = frame_base._elementwise_method(
'transform', restrictions={'axis': 0})
def transpose(self, *args, **kwargs):
raise frame_base.WontImplementError('non-deferred column values')
def unstack(self, *args, **kwargs):
if self._expr.proxy().index.nlevels == 1:
return frame_base.DeferredFrame.wrap(
expressions.ComputedExpression(
'unstack',
lambda df: df.unstack(*args, **kwargs),
[self._expr],
requires_partition_by=partitionings.Index()))
else:
raise frame_base.WontImplementError('non-deferred column values')
update = frame_base._proxy_method(
'update',
inplace=True,
requires_partition_by=partitionings.Index(),
preserves_partition_by=partitionings.Index())
def evaluate(self, expr):
import pandas as pd
import collections
def is_scalar(expr):
return not isinstance(expr.proxy(), pd.core.generic.NDFrame)
def difficulty(partitioning):
"""Imposes an ordering on partitionings where the largest schemes are the
most likely to reveal an error. This order is different from the one
defined by is_subpartitioning_of:
Nothing() > Index() > ... > Index([i,j]) > Index([j]) > Singleton()
"""
if isinstance(partitioning, partitionings.Singleton):
return -float('inf')
elif isinstance(partitioning, partitionings.Index):
if partitioning._levels is None:
return 1_000_000
else:
return len(partitioning._levels)
elif isinstance(partitioning, partitionings.Nothing):
return float('inf')
if expr not in self._bindings:
if is_scalar(expr) or not expr.args():
result = super(PartitioningSession, self).evaluate(expr)
else:
scaler_args = [arg for arg in expr.args() if is_scalar(arg)]
def evaluate_with(input_partitioning):
parts = collections.defaultdict(lambda: Session(
{arg: self.evaluate(arg)
for arg in scaler_args}))
for arg in expr.args():
if not is_scalar(arg):
input = self.evaluate(arg)
for key, part in input_partitioning.test_partition_fn(
input):
parts[key]._bindings[arg] = part
if not parts:
parts[None] # Create at least one entry.
results = []
for session in parts.values():
if any(
len(session.lookup(arg))
for arg in expr.args() if not is_scalar(arg)):
results.append(session.evaluate(expr))
expected_output_partitioning = expr.preserves_partition_by(
) if input_partitioning.is_subpartitioning_of(
expr.preserves_partition_by()) else input_partitioning
if not expected_output_partitioning.check(results):
raise AssertionError(
f"""Expression does not preserve partitioning!
Expression: {expr}
Requires: {expr.requires_partition_by()}
Preserves: {expr.preserves_partition_by()}
Input partitioning: {input_partitioning}
Expected output partitioning: {expected_output_partitioning}
""")
if results:
return pd.concat(results)
else:
# Choose any single session.
return next(iter(parts.values())).evaluate(expr)
# Store random state so it can be re-used for each execution, in case
# the expression is part of a test that relies on the random seed.
random_state = random.getstate()
# Run with all supported partitionings in order of ascending
# "difficulty". This way the final result is computed with the
# most challenging partitioning. Avoids heisenbugs where sometimes
# the result is computed trivially with Singleton partitioning and
# passes.
for input_partitioning in sorted(set([
expr.requires_partition_by(),
partitionings.Nothing(),
partitionings.Index(),
partitionings.Singleton()
]),
key=difficulty):
if not input_partitioning.is_subpartitioning_of(
expr.requires_partition_by()):
continue
random.setstate(random_state)
result = evaluate_with(input_partitioning)
self._bindings[expr] = result
return self._bindings[expr]
