def concat(objs, ignore_index=False):
"""Concatenate DataFrames, Series, or Indices row-wise.
Parameters
----------
objs : list of DataFrame, Series, or Index
ignore_index : bool
Set True to ignore the index of the *objs* and provide a
default range index instead.
Returns
-------
A new object of like type with rows from each object in ``objs``.
"""
if not objs:
raise ValueError("Need at least one object to concatenate")
# no-op for single object
if len(objs) == 1:
return objs[0]
typs = set(type(o) for o in objs)
if len(typs) > 1:
raise ValueError("`concat` expects all objects to be of the same "
"type. Got mix of %r." % [t.__name__ for t in typs])
typ = list(typs)[0]
if typ is DataFrame:
return DataFrame._concat(objs, ignore_index=ignore_index)
elif typ is Series:
return Series._concat(objs)
elif issubclass(typ, Index):
return Index._concat(objs)
else:
raise ValueError("Unknown type %r" % typ)
def concat(objs, axis=0, ignore_index=False, sort=None):
"""Concatenate DataFrames, Series, or Indices row-wise.
Parameters
----------
objs : list of DataFrame, Series, or Index
axis : concatenation axis, 0 - index, 1 - columns
ignore_index : bool
Set True to ignore the index of the *objs* and provide a
default range index instead.
Returns
-------
A new object of like type with rows from each object in ``objs``.
"""
if sort not in (None, False):
raise NotImplementedError("sort parameter is not yet supported")
if not objs:
raise ValueError("Need at least one object to concatenate")
# no-op for single object
if len(objs) == 1:
return objs[0]
typs = set(type(o) for o in objs)
allowed_typs = {Series, DataFrame}
# when axis is 1 (column) we can concat with Series and Dataframes
if axis == 1:
assert typs.issubset(allowed_typs)
df = DataFrame()
for idx, o in enumerate(objs):
if isinstance(o, Series):
name = o.name
if o.name is None:
# pandas uses 0-offset
name = idx - 1
df[name] = o
else:
for col in o.columns:
df[col] = o[col]
return df
if len(typs) > 1:
raise ValueError("`concat` expects all objects to be of the same "
"type. Got mix of %r." % [t.__name__ for t in typs])
typ = list(typs)[0]
if typ is DataFrame:
return DataFrame._concat(objs, axis=axis, ignore_index=ignore_index)
elif typ is Series:
return Series._concat(objs, axis=axis)
elif issubclass(typ, Index):
return Index._concat(objs)
else:
raise ValueError("Unknown type %r" % typ)