mirror of
https://github.com/python/cpython.git
synced 2025-08-31 05:58:33 +00:00
inspect.signautre: Fix functools.partial support. Issue #21117
This commit is contained in:
Yury Selivanov
parent
7ddf3eba90
commit
0fceaf45e2
3 changed files with 145 additions and 92 deletions
133
Lib/inspect.py
133
Lib/inspect.py
|
|
@ -1511,7 +1511,8 @@ def _signature_get_partial(wrapped_sig, partial, extra_args=()):
|
|||
# look like after applying a 'functools.partial' object (or alike)
|
||||
# on it.
|
||||
|
||||
new_params = OrderedDict(wrapped_sig.parameters.items())
|
||||
old_params = wrapped_sig.parameters
|
||||
new_params = OrderedDict(old_params.items())
|
||||
|
||||
partial_args = partial.args or ()
|
||||
partial_keywords = partial.keywords or {}
|
||||
|
|
@ -1525,32 +1526,57 @@ def _signature_get_partial(wrapped_sig, partial, extra_args=()):
|
|||
msg = 'partial object {!r} has incorrect arguments'.format(partial)
|
||||
raise ValueError(msg) from ex
|
||||
|
||||
for arg_name, arg_value in ba.arguments.items():
|
||||
param = new_params[arg_name]
|
||||
if arg_name in partial_keywords:
|
||||
# We set a new default value, because the following code
|
||||
# is correct:
|
||||
#
|
||||
# >>> def foo(a): print(a)
|
||||
# >>> print(partial(partial(foo, a=10), a=20)())
|
||||
# 20
|
||||
# >>> print(partial(partial(foo, a=10), a=20)(a=30))
|
||||
# 30
|
||||
#
|
||||
# So, with 'partial' objects, passing a keyword argument is
|
||||
# like setting a new default value for the corresponding
|
||||
# parameter
|
||||
#
|
||||
# We also mark this parameter with '_partial_kwarg'
|
||||
# flag. Later, in '_bind', the 'default' value of this
|
||||
# parameter will be added to 'kwargs', to simulate
|
||||
# the 'functools.partial' real call.
|
||||
new_params[arg_name] = param.replace(default=arg_value,
|
||||
_partial_kwarg=True)
|
||||
|
||||
elif (param.kind not in (_VAR_KEYWORD, _VAR_POSITIONAL) and
|
||||
not param._partial_kwarg):
|
||||
new_params.pop(arg_name)
|
||||
transform_to_kwonly = False
|
||||
for param_name, param in old_params.items():
|
||||
try:
|
||||
arg_value = ba.arguments[param_name]
|
||||
except KeyError:
|
||||
pass
|
||||
else:
|
||||
if param.kind is _POSITIONAL_ONLY:
|
||||
# If positional-only parameter is bound by partial,
|
||||
# it effectively disappears from the signature
|
||||
new_params.pop(param_name)
|
||||
continue
|
||||
|
||||
if param.kind is _POSITIONAL_OR_KEYWORD:
|
||||
if param_name in partial_keywords:
|
||||
# This means that this parameter, and all parameters
|
||||
# after it should be keyword-only (and var-positional
|
||||
# should be removed). Here's why. Consider the following
|
||||
# function:
|
||||
# foo(a, b, *args, c):
|
||||
# pass
|
||||
#
|
||||
# "partial(foo, a='spam')" will have the following
|
||||
# signature: "(*, a='spam', b, c)". Because attempting
|
||||
# to call that partial with "(10, 20)" arguments will
|
||||
# raise a TypeError, saying that "a" argument received
|
||||
# multiple values.
|
||||
transform_to_kwonly = True
|
||||
# Set the new default value
|
||||
new_params[param_name] = param.replace(default=arg_value)
|
||||
else:
|
||||
# was passed as a positional argument
|
||||
new_params.pop(param.name)
|
||||
continue
|
||||
|
||||
if param.kind is _KEYWORD_ONLY:
|
||||
# Set the new default value
|
||||
new_params[param_name] = param.replace(default=arg_value)
|
||||
|
||||
if transform_to_kwonly:
|
||||
assert param.kind is not _POSITIONAL_ONLY
|
||||
|
||||
if param.kind is _POSITIONAL_OR_KEYWORD:
|
||||
new_param = new_params[param_name].replace(kind=_KEYWORD_ONLY)
|
||||
new_params[param_name] = new_param
|
||||
new_params.move_to_end(param_name)
|
||||
elif param.kind in (_KEYWORD_ONLY, _VAR_KEYWORD):
|
||||
new_params.move_to_end(param_name)
|
||||
elif param.kind is _VAR_POSITIONAL:
|
||||
new_params.pop(param.name)
|
||||
|
||||
return wrapped_sig.replace(parameters=new_params.values())
|
||||
|
||||
|
|
@ -2069,7 +2095,7 @@ class Parameter:
|
|||
`Parameter.KEYWORD_ONLY`, `Parameter.VAR_KEYWORD`.
|
||||
'''
|
||||
|
||||
__slots__ = ('_name', '_kind', '_default', '_annotation', '_partial_kwarg')
|
||||
__slots__ = ('_name', '_kind', '_default', '_annotation')
|
||||
|
||||
POSITIONAL_ONLY = _POSITIONAL_ONLY
|
||||
POSITIONAL_OR_KEYWORD = _POSITIONAL_OR_KEYWORD
|
||||
|
|
@ -2079,8 +2105,7 @@ class Parameter:
|
|||
|
||||
empty = _empty
|
||||
|
||||
def __init__(self, name, kind, *, default=_empty, annotation=_empty,
|
||||
_partial_kwarg=False):
|
||||
def __init__(self, name, kind, *, default=_empty, annotation=_empty):
|
||||
|
||||
if kind not in (_POSITIONAL_ONLY, _POSITIONAL_OR_KEYWORD,
|
||||
_VAR_POSITIONAL, _KEYWORD_ONLY, _VAR_KEYWORD):
|
||||
|
|
@ -2105,8 +2130,6 @@ class Parameter:
|
|||
|
||||
self._name = name
|
||||
|
||||
self._partial_kwarg = _partial_kwarg
|
||||
|
||||
@property
|
||||
def name(self):
|
||||
return self._name
|
||||
|
|
@ -2123,8 +2146,8 @@ class Parameter:
|
|||
def kind(self):
|
||||
return self._kind
|
||||
|
||||
def replace(self, *, name=_void, kind=_void, annotation=_void,
|
||||
default=_void, _partial_kwarg=_void):
|
||||
def replace(self, *, name=_void, kind=_void,
|
||||
annotation=_void, default=_void):
|
||||
'''Creates a customized copy of the Parameter.'''
|
||||
|
||||
if name is _void:
|
||||
|
|
@ -2139,11 +2162,7 @@ class Parameter:
|
|||
if default is _void:
|
||||
default = self._default
|
||||
|
||||
if _partial_kwarg is _void:
|
||||
_partial_kwarg = self._partial_kwarg
|
||||
|
||||
return type(self)(name, kind, default=default, annotation=annotation,
|
||||
_partial_kwarg=_partial_kwarg)
|
||||
return type(self)(name, kind, default=default, annotation=annotation)
|
||||
|
||||
def __str__(self):
|
||||
kind = self.kind
|
||||
|
|
@ -2169,17 +2188,6 @@ class Parameter:
|
|||
id(self), self.name)
|
||||
|
||||
def __eq__(self, other):
|
||||
# NB: We deliberately do not compare '_partial_kwarg' attributes
|
||||
# here. Imagine we have a following situation:
|
||||
#
|
||||
# def foo(a, b=1): pass
|
||||
# def bar(a, b): pass
|
||||
# bar2 = functools.partial(bar, b=1)
|
||||
#
|
||||
# For the above scenario, signatures for `foo` and `bar2` should
|
||||
# be equal. '_partial_kwarg' attribute is an internal flag, to
|
||||
# distinguish between keyword parameters with defaults and
|
||||
# keyword parameters which got their defaults from functools.partial
|
||||
return (issubclass(other.__class__, Parameter) and
|
||||
self._name == other._name and
|
||||
self._kind == other._kind and
|
||||
|
|
@ -2219,12 +2227,7 @@ class BoundArguments:
|
|||
def args(self):
|
||||
args = []
|
||||
for param_name, param in self._signature.parameters.items():
|
||||
if (param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY) or
|
||||
param._partial_kwarg):
|
||||
# Keyword arguments mapped by 'functools.partial'
|
||||
# (Parameter._partial_kwarg is True) are mapped
|
||||
# in 'BoundArguments.kwargs', along with VAR_KEYWORD &
|
||||
# KEYWORD_ONLY
|
||||
if param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY):
|
||||
break
|
||||
|
||||
try:
|
||||
|
|
@ -2249,8 +2252,7 @@ class BoundArguments:
|
|||
kwargs_started = False
|
||||
for param_name, param in self._signature.parameters.items():
|
||||
if not kwargs_started:
|
||||
if (param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY) or
|
||||
param._partial_kwarg):
|
||||
if param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY):
|
||||
kwargs_started = True
|
||||
else:
|
||||
if param_name not in self.arguments:
|
||||
|
|
@ -2332,18 +2334,14 @@ class Signature:
|
|||
name = param.name
|
||||
|
||||
if kind < top_kind:
|
||||
msg = 'wrong parameter order: {} before {}'
|
||||
msg = 'wrong parameter order: {!r} before {!r}'
|
||||
msg = msg.format(top_kind, kind)
|
||||
raise ValueError(msg)
|
||||
elif kind > top_kind:
|
||||
kind_defaults = False
|
||||
top_kind = kind
|
||||
|
||||
if (kind in (_POSITIONAL_ONLY, _POSITIONAL_OR_KEYWORD) and
|
||||
not param._partial_kwarg):
|
||||
# If we have a positional-only or positional-or-keyword
|
||||
# parameter, that does not have its default value set
|
||||
# by 'functools.partial' or other "partial" signature:
|
||||
if kind in (_POSITIONAL_ONLY, _POSITIONAL_OR_KEYWORD):
|
||||
if param.default is _empty:
|
||||
if kind_defaults:
|
||||
# No default for this parameter, but the
|
||||
|
|
@ -2518,15 +2516,6 @@ class Signature:
|
|||
parameters_ex = ()
|
||||
arg_vals = iter(args)
|
||||
|
||||
if partial:
|
||||
# Support for binding arguments to 'functools.partial' objects.
|
||||
# See 'functools.partial' case in 'signature()' implementation
|
||||
# for details.
|
||||
for param_name, param in self.parameters.items():
|
||||
if (param._partial_kwarg and param_name not in kwargs):
|
||||
# Simulating 'functools.partial' behavior
|
||||
kwargs[param_name] = param.default
|
||||
|
||||
while True:
|
||||
# Let's iterate through the positional arguments and corresponding
|
||||
# parameters
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue