#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import absolute_import
import functools
import inspect
import sys
from typing import Any
from typing import Callable
from typing import Dict
from typing import List
from typing import Optional
from typing import Union
import pandas as pd
from apache_beam.dataframe import expressions
from apache_beam.dataframe import partitionings
# pylint: disable=deprecated-method
if sys.version_info < (3, ):
_getargspec = inspect.getargspec
def _unwrap(func):
while hasattr(func, '__wrapped__'):
func = func.__wrapped__
return func
else:
_getargspec = inspect.getfullargspec
_unwrap = inspect.unwrap
[docs]class DeferredBase(object):
_pandas_type_map = {} # type: Dict[Union[type, None], type]
def __init__(self, expr):
self._expr = expr
@classmethod
def _register_for(cls, pandas_type):
def wrapper(deferred_type):
cls._pandas_type_map[pandas_type] = deferred_type
return deferred_type
return wrapper
[docs] @classmethod
def wrap(cls, expr):
proxy_type = type(expr.proxy())
if proxy_type in cls._pandas_type_map:
wrapper_type = cls._pandas_type_map[proxy_type]
else:
if expr.requires_partition_by() != partitionings.Singleton():
raise ValueError(
'Scalar expression %s of type %s partitoned by non-singleton %s' %
(expr, proxy_type, expr.requires_partition_by()))
wrapper_type = _DeferredScalar
return wrapper_type(expr)
def _elementwise(self, func, name=None, other_args=(), inplace=False):
return _elementwise_function(func, name, inplace=inplace)(self, *other_args)
def __reduce__(self):
return UnusableUnpickledDeferredBase, (str(self), )
[docs]class UnusableUnpickledDeferredBase(object):
"""Placeholder object used to break the transitive pickling chain in case a
DeferredBase accidentially gets pickled (e.g. as part of globals).
Trying to use this object after unpickling is a bug and will result in an
error.
"""
def __init__(self, name):
self._name = name
def __repr__(self):
return 'UnusablePickledDeferredBase(%r)' % self.name
[docs]class DeferredFrame(DeferredBase):
@property
def dtypes(self):
return self._expr.proxy().dtypes
class _DeferredScalar(DeferredBase):
pass
DeferredBase._pandas_type_map[None] = _DeferredScalar
[docs]def name_and_func(method):
if isinstance(method, str):
return method, lambda df, *args, **kwargs: getattr(df, method)(*args, **
kwargs)
else:
return method.__name__, method
def _elementwise_method(func, name=None, restrictions=None, inplace=False):
return _proxy_method(
func,
name,
restrictions,
inplace,
requires_partition_by=partitionings.Nothing(),
preserves_partition_by=partitionings.Singleton())
def _proxy_method(
func,
name=None,
restrictions=None,
inplace=False,
requires_partition_by=partitionings.Singleton(),
preserves_partition_by=partitionings.Nothing()):
if name is None:
name, func = name_and_func(func)
if restrictions is None:
restrictions = {}
return _proxy_function(
func,
name,
restrictions,
inplace,
requires_partition_by,
preserves_partition_by)
def _elementwise_function(func, name=None, restrictions=None, inplace=False):
return _proxy_function(
func,
name,
restrictions,
inplace,
requires_partition_by=partitionings.Nothing(),
preserves_partition_by=partitionings.Singleton())
def _proxy_function(
func, # type: Union[Callable, str]
name=None, # type: Optional[str]
restrictions=None, # type: Optional[Dict[str, Union[Any, List[Any]]]]
inplace=False, # type: bool
requires_partition_by=partitionings.Singleton(), # type: partitionings.Partitioning
preserves_partition_by=partitionings.Nothing(), # type: partitionings.Partitioning
):
if name is None:
if isinstance(func, str):
name = func
else:
name = func.__name__
if restrictions is None:
restrictions = {}
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)
return wrapper
def _agg_method(func):
def wrapper(self, *args, **kwargs):
return self.agg(func, *args, **kwargs)
return wrapper
[docs]def wont_implement_method(msg):
def wrapper(self, *args, **kwargs):
raise WontImplementError(msg)
return wrapper
[docs]def not_implemented_method(op, jira='BEAM-9547'):
def wrapper(self, *args, **kwargs):
raise NotImplementedError("'%s' is not yet supported (%s)" % (op, jira))
return wrapper
[docs]def copy_and_mutate(func):
def wrapper(self, *args, **kwargs):
copy = self.copy()
func(copy, *args, **kwargs)
return copy
return wrapper
[docs]def maybe_inplace(func):
@functools.wraps(func)
def wrapper(self, inplace=False, **kwargs):
result = func(self, **kwargs)
if inplace:
self._expr = result._expr
else:
return result
return wrapper
[docs]def args_to_kwargs(base_type):
def wrap(func):
arg_names = _getargspec(_unwrap(getattr(base_type, func.__name__))).args
@functools.wraps(func)
def wrapper(*args, **kwargs):
for name, value in zip(arg_names, args):
if name in kwargs:
raise TypeError(
"%s() got multiple values for argument '%s'" %
(func.__name__, name))
kwargs[name] = value
return func(**kwargs)
return wrapper
return wrap
[docs]def populate_defaults(base_type):
def wrap(func):
base_argspec = _getargspec(_unwrap(getattr(base_type, func.__name__)))
if not base_argspec.defaults:
return func
arg_to_default = dict(
zip(
base_argspec.args[-len(base_argspec.defaults):],
base_argspec.defaults))
unwrapped_func = _unwrap(func)
# args that do not have defaults in func, but do have defaults in base
func_argspec = _getargspec(unwrapped_func)
num_non_defaults = len(func_argspec.args) - len(func_argspec.defaults or ())
defaults_to_populate = set(
func_argspec.args[:num_non_defaults]).intersection(
arg_to_default.keys())
@functools.wraps(func)
def wrapper(**kwargs):
for name in defaults_to_populate:
if name not in kwargs:
kwargs[name] = arg_to_default[name]
return func(**kwargs)
return wrapper
return wrap
[docs]class WontImplementError(NotImplementedError):
"""An subclass of NotImplementedError to raise indicating that implementing
the given method is infeasible.
Raising this error will also prevent this doctests from being validated
when run with the beam dataframe validation doctest runner.
"""
pass