def group_by(pcollection, fields, **options):
"""
对pcollection按字段group by
Args:
pcollection (SchemaPCollection): 输入数据集SchemaPCollection(用来表示结构化的，带字段的PCollection), 可以当作每个元素是一个dict的PCollection来用
fields (Iterable): 如果fields为一个str，则会按“,”进行切割，然后按切割出的字段进行分组。
如果fields为一个list/tuple，则直接按list中的多个字段进行分组
Returns:
SchemaPCollection: 每个key为group的字段所组成的一个dict，每个value是一个PCollection，包含所有的列。
Examples:
>>> from bigflow import base, schema
>>> p = base.Pipeline.create('local')
>>> analytics = p.parallelize([('a,b,c', 1), ('b,c', 2), ('a,c', 3), ('a,b', 2), ('a,d', 1)])
>>> .apply(schema.tuple_to_dict, ['websites', 'clicknum'])
>>> .apply(schema.select, lambda cols: {
>>> 'website': cols['websites'].flat_map(lambda line: line.split(',')),
>>> 'clicknum': cols['clicknum']
>>> }).apply(schema.group_by, ['website'])
>>> .apply_values(transforms.first)
>>> .apply(schema.flatten)
>>> print analytics.get()
输出结果为:
[{'website': 'a', 'clicknum': 1}, {'website': 'b', 'clicknum': 1}, {'website': 'c', 'clicknum': 1},
{'website': 'd', 'clicknum': 1}]
"""
pcollection = _transform_schema_pcollection(pcollection)
if _is_tuple_serde(pcollection.serde()):
def _select_fields(tup, fields):
""" 内部函数 """
return tuple(tup[field] for field in fields)
from bigflow import schema_pcollection
return pcollection.group_by(lambda record: _select_fields(record, fields),
key_serde=serde.of(tuple(_origin_serde(pcollection.serde())[field]
for field in fields)), **options)\
.apply_values(lambda record: schema_pcollection.SchemaPCollection(record))
def _select_fields(dct, fields):
""" 内部函数 """
return dict((field, dct[field]) for field in fields)
if isinstance(fields, str):
fields = ''.join(fields.split()).split(',')
from bigflow import schema_pcollection
return pcollection.group_by(lambda record: _select_fields(record, fields),
key_serde=_get_serde_of_fields(pcollection.serde(), fields,
pcollection.pipeline().default_objector()), **options) \
.apply_values(lambda record: schema_pcollection.SchemaPCollection(record))
def _ret_dict_handler(ret_dict, record_val):
""" 内部函数 """
inter_type_keys = []
inter_type_values = []
inter_type_flag = False
ptype_keys = []
ptype_values = []
ptype_flag = False
for key, value in ret_dict.items():
if isinstance(value, ptype.PType):
ptype_keys.append((key, value.serde()))
ptype_values.append(value)
ptype_flag = True
else:
inter_type_keys.append((key, type(value)))
inter_type_values.append(value)
inter_type_flag = True
if ptype_flag and inter_type_flag:
ptype_keys.extend(inter_type_keys)
return tuple_to_dict(transforms.cartesian(*ptype_values)\
.apply(transforms.map, lambda record: record + tuple(inter_type_values)),
ptype_keys)
elif not ptype_flag and inter_type_flag:
from bigflow import schema_pcollection
return schema_pcollection.SchemaPCollection(
record_val.apply(
transforms.map,
lambda record: dict(
zip(tuple(key_sd[0] for key_sd in inter_type_keys),
inter_type_values)),
serde=of(dict(inter_type_keys))))
else:
return tuple_to_dict(transforms.cartesian(*ptype_values), ptype_keys)
def tuple_to_dict(pcollection, fields):
"""
从每个元素是tuple的PCollection转化成一个SchemaPCollection。
Args:
pcollection (PCollection): 输入PCollection，每个元素是一个tuple
fields (list): fields中每个元素是一个tuple(key, value), key是字段名，value是相应字段所用的serde,
若fields中每个元素是一个str表示字段名, 则表示所有类型都是可被marshal序列化的类型
Returns:
SchemaPCollection: 用来表示结构化的，带字段的PCollection(FieldsDict)，它拥有普通PCollection的所有操作
"""
fields = _str_to_list(fields)
from bigflow import schema_pcollection
order_fields = []
serde_fields = {}
for field in fields:
if isinstance(field, tuple):
order_fields.append(field[0])
serde_fields[field[0]] = field[1]
else:
order_fields.append(field)
serde_fields[field] = serde._
return schema_pcollection.SchemaPCollection(
pcollection.map(lambda record: dict(zip(order_fields, record)),
serde=of(serde_fields)))
def agg(pcollection, agg_fn, *args):
"""
把PCollection的全部数据进行聚合
Args:
pcollection (SchemaPCollection): 输入数据集SchemaPCollection(用来表示结构化的，带字段的PCollection), 可以当作每个元素是一个dict的PCollection来用
agg_fn (callable): 一个函数，表示对每个字段进行怎么样的聚合，该函数将传入一个dict类型的参数，dict的key是所有的字段名，每个value是一个
PCollection，表示该字段的全部数据。 用户需要返回一个dict，dict的key是要输出的字段，value是一个分布式数据集(PCollection
或PObject)， 表示相关字段下的数据。 最终多个字段下的多个数据集进行笛卡尔积，拼接成最终返回的数据集。
*args (object): 变换所需要的参数列表
Returns:
SchemaPCollection: 返回一个每个元素是一个dict的pcollection, 其中所有元素输出的几个pcollection进行笛卡尔积并添加字段名后的结果
Examples:
>>> from bigflow import base, schema
>>> p = base.Pipeline.create('local')
>>> analytics = p.parallelize([('a,b,c', 1), ('b,c', 2), ('a,c', 3), ('a,b', 2), ('a,d', 1)])
>>> .apply(schema.tuple_to_dict, ['websites', 'clicknum'])
>>> .apply(schema.select, lambda cols: {
>>> 'website': cols['websites'].flat_map(lambda line: line.split(',')),
>>> 'clicknum': cols['clicknum']
>>> }).apply(schema.group_by, ['website'])
>>> .apply_values(schema.agg, lambda cols: {
>>> 'max_click_num': cols['clicknum'].max(),
>>> 'sum_click_num': cols['clicknum'].sum(),
>>> 'avg_click_num': cols['clicknum'].sum() / cols['clicknum'].count()
>>> }).apply(schema.flatten)
>>> print analytics.get()
输出结果为:
[{'sum_click_num': 7, 'website': 'a', 'avg_click_num': 1, 'max_click_num': 3},
{'sum_click_num': 6, 'website': 'c', 'avg_click_num': 2, 'max_click_num': 3},
{'sum_click_num': 5, 'website': 'b', 'avg_click_num': 1, 'max_click_num': 2},
{'sum_click_num': 1, 'website': 'd', 'avg_click_num': 1, 'max_click_num': 1}]
"""
pcollection = _transform_schema_pcollection(pcollection)
if _is_tuple_serde(pcollection.serde()):
def _pack_udf():
""" 内部函数 """
tp = list(pcollection.apply(_select_cols_tp))
tp.extend(args)
ret_tuple = agg_fn(*tp)
return _ret_tuple_handler(ret_tuple, tp[0])
from bigflow import schema_pcollection
return schema_pcollection.SchemaPCollection(_pack_udf())
def _pack_udf(val, *args):
""" 内部函数 """
record_val = val[-1]
ret_dict = agg_fn(dict(zip(agg_fields, val[:-1])), *args)
return _ret_dict_handler(ret_dict, record_val)
agg_fields = pcollection._get_fields()
return _pack_udf(pcollection.apply(_select_cols, agg_fields), *args)
def full_join(*pcollections, **options):
"""
对多个输入SchemaPCollection，根据指定的字段(dict)对SchemaPCollection做内连接操作,
连接结果为(fields, (value1, value2, ..., value n)), 若第m个SchemaPCollection没有元素,
则value m为None
Args:
*pcollection (SchemaPCollection): 输入的多个SchemaPCollection
**options: 配置选项，需要配置fields=str/tuple/list(一个列表、元组、一个逗号分隔的字符串，表示指定的字段)
Returns:
SchemaPCollection: 连接结果
Examples:
>>> from bigflow import base, schema, transforms
>>> p = base.Pipeline.create('local')
>>> p1 = p.parallelize([('a', 2), ('e', 4), ('c', 6)])
>>> sp1 = p1.apply(schema.tuple_to_dict, ['websites', 'clicknum'])
>>> p2 = p.parallelize([('a', 9), ('b', 8), ('d', 7)])
>>> sp2 = p2.apply(schema.tuple_to_dict, ['websites', 'click'])
>>> csp = sp1.apply(schema.full_join, sp2, fields=['websites'])
>>> csp.get()
输出结果为：
[({'clicknum': 4, 'websites': 'e'}, {'click': None, 'websites': None}),
({'clicknum': None, 'websites': None}, {'click': 8, 'websites': 'b'}),
({'clicknum': None, 'websites': None}, {'click': 7, 'websites': 'd'}),
({'clicknum': 2, 'websites': 'a'}, {'click': 9, 'websites': 'a'}),
({'clicknum': 6, 'websites': 'c'}, {'click': None, 'websites': None})]
"""
if len(pcollections) < 2:
raise ValueError("require at least 2 pcollections")
fields = options.get('fields', None)
from bigflow import schema_pcollection
pc = transforms.full_join(*_check_set_args(fields, pcollections))
none_dict = _get_none_dict(pcollections)
ret = schema_pcollection.SchemaPCollection(
pc.apply(transforms.map,
lambda tp: _none_to_dict(tp, none_dict),
serde=_value_serde(pc.serde())))
# default: merge = False, don't merge the result
merge = options.get("merge", False)
if not merge:
return ret
else:
return _merge_result_after_join(ret, "full_join")
def _trans_to_sp(*records):
""" 内部函数 """
from bigflow import schema_pcollection
return tuple(
schema_pcollection.SchemaPCollection(record) for record in records)
def flatten(ptype):
"""
把PTable的所有value拼接上key，并打平成一个SchemaPCollection
Args:
ptype (PTable): 输入数据集，需要是一个PTable，key,value都必须为字典
Returns:
SchemaPCollection: 返回的SchemaPCollection拥有key,value所有的字段，如果key,value中有相同字段，则以value为准
Examples:
>>> from bigflow import base, schema
>>> p = base.Pipeline.create('local')
>>> analytics = p.parallelize([('a,b,c', 1), ('b,c', 2), ('a,c', 3), ('a,b', 2), ('a,d', 1)])
>>> .apply(schema.tuple_to_dict, ['websites', 'clicknum'])
>>> .apply(schema.select, lambda cols: {
>>> 'website': cols['websites'].flat_map(lambda line: line.split(',')),
>>> 'clicknum': cols['clicknum']
>>> }).apply(schema.group_by, ['website'])
>>> .apply(schema.flatten)
>>> print analytics.get()
输出结果为:
[{'website': 'a', 'clicknum': 1}, {'website': 'b', 'clicknum': 1}, {'website': 'c', 'clicknum': 1},
{'website': 'b', 'clicknum': 2}, {'website': 'c', 'clicknum': 2}, {'website': 'a', 'clicknum': 3},
{'website': 'c', 'clicknum': 3}, {'website': 'a', 'clicknum': 2}, {'website': 'b', 'clicknum': 2},
{'website': 'a', 'clicknum': 1}, {'website': 'd', 'clicknum': 1}]
"""
def _new_dict(*dicts):
""" 内部函数 """
ret = {}
for dct in dicts:
ret.update(dct)
return ret
def _merge_kv(tp, level):
""" 内部函数 """
kvs = []
for i in xrange(level):
kvs.append(tp[0])
tp = tp[1]
kvs.append(tp)
return kvs
def _merge_serde(serdes, dft=None):
""" 内部函数 """
ret = {}
for sd in serdes:
if not isinstance(serde.origin(sd), FieldsDictSerde):
return dft
for field, field_serde in serde.origin(
sd)._fields_to_types.iteritems():
ret[field] = field_serde
return of(ret)
if not isinstance(ptype, ptable.PTable):
raise ValueError("flatten should only be applied on PTable")
level = ptype.nested_level() + 1
from bigflow import schema_pcollection
return schema_pcollection.SchemaPCollection(ptype.flatten().map(
lambda kv: _new_dict(*_merge_kv(kv, level)),
serde=_merge_serde(ptype.key_serdes() + [ptype.serde()],
ptype.pipeline().default_objector())))
def select(pcollection, select_fn, *args):
"""
对每条数据选择一些字段进行变换
Args:
pcollection (SchemaPCollection): 输入数据集SchemaPCollection(用来表示结构化的, 带字段的PCollection), 可以当作每个元素是一个dict的PCollection来用
select_fn (callable): 一个函数，表示每条记录要进行什么样的变换，该函数将传入一个dict类型的参数，dict的key是所有的字段名，
每个value是一个PObject，表示本条记录中该字段的数据。 用户需要返回一个dict，dict的key是要输出的字段，
value是一个分布式数据集(PCollection或PObject)， 表示相关字段下的数据。 最终多个字段下的多个数据集进
行笛卡尔积，拼接成最终返回的数据集。
*args (object): 变换所需要的参数列表
Returns:
SchemaPCollection: 每个元素是一个dict的pcollection,
这个SchemaPCollection中所有元素相当于对原数据每条数据进行一次select_fn处理，
处理后返回的tuple中的所有数据集进行笛卡尔积，
最终再把所有输入数据处理后得出的结果拼成一个数据集。
Examples:
>>> from bigflow import base, schema
>>> p = base.Pipeline.create('local')
>>> analytics = p.parallelize([('a,b,c', 1), ('b,c', 2), ('a,c', 3), ('a,b', 2), ('a,d', 1)])
>>> .apply(schema.tuple_to_dict, ['websites', 'clicknum'])
>>> .apply(schema.select, lambda cols: {
>>> 'website': cols['websites'].flat_map(lambda line: line.split(',')),
>>> 'clicknum': cols['clicknum']
>>> })
>>> print analytics.get()
输出结果为
[{'website': 'a', 'clicknum': 1}, {'website': 'b', 'clicknum': 1}, {'website': 'c', 'clicknum': 1},
{'website': 'b', 'clicknum': 2}, {'website': 'c', 'clicknum': 2}, {'website': 'a', 'clicknum': 3},
{'website': 'c', 'clicknum': 3}, {'website': 'a', 'clicknum': 2}, {'website': 'b', 'clicknum': 2},
{'website': 'a', 'clicknum': 1}, {'website': 'd', 'clicknum': 1}]
>>> from bigflow import schema
>>> from bigflow import transforms
>>> from bigflow import base
>>> pl = base.Pipeline.create("local")
>>> raw_data = [["xiaoming", "school_1", 12, 150, 90], ]
>>> data = pl.parallelize(raw_data) \
>>> .apply(schema.tuple_to_dict,
>>> [("name", str),
>>> ("school", str),
>>> ("age", int),
>>> ("height", int),
>>> ("weight", int)])
>>> fields = {
>>> # 复用bigflow提供的transforms：传入一个tuple，提供transforms及自定义函数
>>> "name": (transforms.map, lambda name: "My name is " + name),
>>> # 提供变化函数：传入一个function
>>> "school": lambda school: "My school is " + school,
>>> }
>>> output = schema.select(data, fields)
>>> print output.get()
输出结果为
[{'school': 'My school is school_1', 'name': 'My name is xiaoming'}]
"""
if isinstance(select_fn, list) or isinstance(
select_fn, tuple) or isinstance(select_fn, str):
cols = _str_to_list(select_fn)
return pcollection.map(
lambda record: {col: record.get(col)
for col in cols},
serde=of({col: serde._
for col in cols}))
pcollection = _transform_schema_pcollection(pcollection)
if isinstance(select_fn, dict):
def wrapper_of_udf(select_fields):
fields_fn = select_fields
def _apply_udf_in_cols(cols, *args):
""" only return columns which user select """
result = {}
for field, tf in fields_fn.items():
if callable(tf):
result[field] = cols[field].apply(tf)
elif isinstance(tf, tuple):
result[field] = cols[field].apply(*tf)
else:
result[field] = tf
return result
return _apply_udf_in_cols
return select(pcollection, wrapper_of_udf(select_fn))
if _is_tuple_serde(pcollection.serde()):
def _pack_udf(*val):
""" 内部函数 """
ret_tuple = select_fn(*val)
return _ret_tuple_handler(ret_tuple, val[0])
from bigflow import schema_pcollection
return schema_pcollection.SchemaPCollection(
pcollection.apply(
group_by_every_record.group_by_every_record).apply_values(
transforms.first).apply_values(
_select_cols_tp).apply_values(_pack_udf,
*args).flatten_values())
def _pack_udf(*val):
""" 内部函数 """
sep_postion = len(select_fields) + 1
record_val = val[sep_postion - 1]
ret_dict = {}
if len(val) > sep_postion:
shard_pts = val[sep_postion:]
ret_dict = select_fn(
dict(zip(select_fields, val[0:sep_postion - 1])), *shard_pts)
else:
ret_dict = select_fn(
dict(zip(select_fields, val[0:sep_postion - 1])))
return _ret_dict_handler(ret_dict, record_val)
select_fields = pcollection._get_fields()
from bigflow import schema_pcollection
return schema_pcollection.SchemaPCollection(
pcollection.apply(
group_by_every_record.group_by_every_record).apply_values(
transforms.first).apply_values(_select_cols,
select_fields).apply_values(
_pack_udf,
*args).flatten_values())
def _transform_schema_pcollection(pcollection):
""" 内部函数 """
from bigflow import schema_pcollection
return schema_pcollection.SchemaPCollection(pcollection)
def transform_from_node(self, load_node, pipeline):
"""
内部接口
"""
from bigflow import schema
if self.fields is None:
raise ValueError('''columns is necessary，(1) columns(list)，
each item in columns is string, SchemaPCollection's element
is dict, (2) columns(int)，SchemaPCollection's element is tuple. eg.
columns=3 or columns=[(xx, int), (yy, str)] or columns=[xx, yy],
(3) columns(list), each item in columns is base type in [int, float, str]'''
)
if isinstance(self.fields, tuple):
self.fields = list(self.fields)
fields_type = []
ignore_overflow = self.ignore_overflow
ignore_illegal_line = self.ignore_illegal_line
if isinstance(self.fields, list):
def get_fields_type(fields):
"""内部函数"""
fields_type = []
for field in fields:
if isinstance(field, tuple):
if field[1] in [int, str, float]:
fields_type.append(field[1])
else:
raise ValueError(
'''columns is list(field name or data type),
data type(int/str/float)''')
elif field in [int, str, float]:
fields_type.append(field)
elif isinstance(field, str):
fields_type.append(str)
else:
raise ValueError(
'''columns is list(field name or data type),
data type(int/str/float)''')
return fields_type
fields_type = get_fields_type(self.fields)
ret = super(SchemaTextFile, self)\
.transform_from_node(load_node, pipeline)\
.flat_map(entity.SplitStringToTypes(self.sep,
fields_type,
ignore_overflow,
ignore_illegal_line),
serde=serde.of(tuple(fields_type)))
if self.fields[0] in [int, float, str]:
return ret
else:
ret = ret.apply(schema.tuple_to_dict, self.fields)
return ret
elif isinstance(self.fields, int):
from bigflow import schema_pcollection
return schema_pcollection.SchemaPCollection(super(SchemaTextFile, self)
.transform_from_node(load_node, pipeline)\
.flat_map(entity.SplitStringToTypes(self.sep,
[str for _ in xrange(self.fields)],
True,
ignore_illegal_line),
serde=serde.of(tuple(serde.StrSerde() for index in xrange(self.fields)))))
else:
raise ValueError("columns is list(field name)，or int(row number)")
