bpo-39990: try resolving type hints in pydoc

Doc/library/inspect.rst

@@ -559,7 +559,7 @@ The Signature object represents the call signature of a callable object and its
 return annotation. To retrieve a Signature object, use the :func:`signature`
 function.
 
-.. function:: signature(callable, \*, follow_wrapped=True)
+.. function:: signature(callable, \*, follow_wrapped=True, resolve_type_hints=False)
 
  Return a :class:`Signature` object for the given ``callable``::
 
@@ -588,6 +588,9 @@ function.
  to it are positional-only. For more info, see
  :ref:`the FAQ entry on positional-only parameters <faq-positional-only-arguments>`.
 
+ .. versionadded:: 3.9
+ ``resolve_type_hints`` parameter. Pass ``True`` to resolve the type annotations.
+
  .. versionadded:: 3.5
  ``follow_wrapped`` parameter. Pass ``False`` to get a signature of
  ``callable`` specifically (``callable.__wrapped__`` will not be used to
@@ -671,7 +674,7 @@ function.
  >>> str(new_sig)
  "(a, b) -> 'new return anno'"
 
- .. classmethod:: Signature.from_callable(obj, \*, follow_wrapped=True)
+ .. classmethod:: Signature.from_callable(obj, \*, follow_wrapped=True, resolve_type_hints=False)
 
  Return a :class:`Signature` (or its subclass) object for a given callable
  ``obj``. Pass ``follow_wrapped=False`` to get a signature of ``obj``
@@ -684,6 +687,9 @@ function.
  sig = MySignature.from_callable(min)
  assert isinstance(sig, MySignature)
 
+ .. versionadded:: 3.9
+ ``resolve_type_hints`` parameter. Pass ``True`` to resolve the type annotations.
+
  .. versionadded:: 3.5
 
 

Lib/inspect.py

@@ -2136,7 +2136,7 @@ def _signature_from_builtin(cls, func, skip_bound_arg=True):
  return _signature_fromstr(cls, func, s, skip_bound_arg)
 
 
-def _signature_from_function(cls, func, skip_bound_arg=True):
+def _signature_from_function(cls, func, skip_bound_arg=True, resolve_type_hints=False):
  """Private helper: constructs Signature for the given python function."""
 
  is_duck_function = False
@@ -2162,10 +2162,15 @@ def _signature_from_function(cls, func, skip_bound_arg=True):
  positional = arg_names[:pos_count]
  keyword_only_count = func_code.co_kwonlyargcount
  keyword_only = arg_names[pos_count:pos_count + keyword_only_count]
- annotations = func.__annotations__
  defaults = func.__defaults__
  kwdefaults = func.__kwdefaults__
 
+ if resolve_type_hints:
+ import typing
+ annotations = typing.get_type_hints(func)
+ else:
+ annotations = func.__annotations__
+
  if defaults:
  pos_default_count = len(defaults)
  else:
@@ -2233,6 +2238,7 @@ def _signature_from_function(cls, func, skip_bound_arg=True):
 def _signature_from_callable(obj, *,
  follow_wrapper_chains=True,
  skip_bound_arg=True,
+ resolve_type_hints=False,
  sigcls):
 
  """Private helper function to get signature for arbitrary
@@ -2249,6 +2255,7 @@ def _signature_from_callable(obj, *,
  obj.__func__,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
 
  if skip_bound_arg:
@@ -2267,6 +2274,7 @@ def _signature_from_callable(obj, *,
  obj,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
 
  try:
@@ -2298,6 +2306,7 @@ def _signature_from_callable(obj, *,
  partialmethod.func,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
 
  sig = _signature_get_partial(wrapped_sig, partialmethod, (None,))
@@ -2317,7 +2326,8 @@ def _signature_from_callable(obj, *,
  # If it's a pure Python function, or an object that is duck type
  # of a Python function (Cython functions, for instance), then:
  return _signature_from_function(sigcls, obj,
- skip_bound_arg=skip_bound_arg)
+ skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints)
 
  if _signature_is_builtin(obj):
  return _signature_from_builtin(sigcls, obj,
@@ -2328,6 +2338,7 @@ def _signature_from_callable(obj, *,
  obj.func,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
  return _signature_get_partial(wrapped_sig, obj)
 
@@ -2343,6 +2354,7 @@ def _signature_from_callable(obj, *,
  call,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
  else:
  # Now we check if the 'obj' class has a '__new__' method
@@ -2352,6 +2364,7 @@ def _signature_from_callable(obj, *,
  new,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
  else:
  # Finally, we should have at least __init__ implemented
@@ -2361,6 +2374,7 @@ def _signature_from_callable(obj, *,
  init,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
 
  if sig is None:
@@ -2411,6 +2425,7 @@ def _signature_from_callable(obj, *,
  call,
  follow_wrapper_chains=follow_wrapper_chains,
  skip_bound_arg=skip_bound_arg,
+ resolve_type_hints=resolve_type_hints,
  sigcls=sigcls)
  except ValueError as ex:
  msg = 'no signature found for{!r}'.format(obj)
@@ -2863,10 +2878,11 @@ def from_builtin(cls, func):
  return _signature_from_builtin(cls, func)
 
  @classmethod
- def from_callable(cls, obj, *, follow_wrapped=True):
+ def from_callable(cls, obj, *, follow_wrapped=True, resolve_type_hints=False):
  """Constructs Signature for the given callable object."""
  return _signature_from_callable(obj, sigcls=cls,
- follow_wrapper_chains=follow_wrapped)
+ follow_wrapper_chains=follow_wrapped,
+ resolve_type_hints=resolve_type_hints)
 
  @property
  def parameters(self):
@@ -3114,9 +3130,10 @@ def __str__(self):
  return rendered
 
 
-def signature(obj, *, follow_wrapped=True):
+def signature(obj, *, follow_wrapped=True, resolve_type_hints=False):
  """Get a signature object for the passed callable."""
- return Signature.from_callable(obj, follow_wrapped=follow_wrapped)
+ return Signature.from_callable(obj, follow_wrapped=follow_wrapped,
+ resolve_type_hints=resolve_type_hints)
 
 
 def _main():

Lib/pydoc.py

@@ -907,9 +907,12 @@ def spilldata(msg, attrs, predicate):
 
  decl = ''
  try:
- signature = inspect.signature(object)
- except (ValueError, TypeError):
- signature = None
+ signature = inspect.signature(object, resolve_type_hints=True)
+ except (NameError, AttributeError, SyntaxError, TypeError, ValueError):
+ try:
+ signature = inspect.signature(object, resolve_type_hints=False)
+ except (ValueError, TypeError):
+ signature = None
  if signature:
  argspec = str(signature)
  if argspec and argspec != '()':
@@ -967,9 +970,12 @@ def docroutine(self, object, name=None, mod=None,
  argspec = None
  if inspect.isroutine(object):
  try:
- signature = inspect.signature(object)
- except (ValueError, TypeError):
- signature = None
+ signature = inspect.signature(object, resolve_type_hints=True)
+ except (NameError, AttributeError, SyntaxError, TypeError, ValueError):
+ try:
+ signature = inspect.signature(object, resolve_type_hints=False)
+ except (ValueError, TypeError):
+ signature = None
  if signature:
  argspec = str(signature)
  if realname == '<lambda>':
@@ -1226,9 +1232,12 @@ def makename(c, m=object.__module__):
  push = contents.append
 
  try:
- signature = inspect.signature(object)
- except (ValueError, TypeError):
- signature = None
+ signature = inspect.signature(object, resolve_type_hints=True)
+ except (NameError, AttributeError, SyntaxError, TypeError, ValueError):
+ try:
+ signature = inspect.signature(object, resolve_type_hints=False)
+ except (ValueError, TypeError):
+ signature = None
  if signature:
  argspec = str(signature)
  if argspec and argspec != '()':
@@ -1397,9 +1406,12 @@ def docroutine(self, object, name=None, mod=None, cl=None):
 
  if inspect.isroutine(object):
  try:
- signature = inspect.signature(object)
- except (ValueError, TypeError):
- signature = None
+ signature = inspect.signature(object, resolve_type_hints=True)
+ except (NameError, AttributeError, SyntaxError, TypeError, ValueError):
+ try:
+ signature = inspect.signature(object, resolve_type_hints=False)
+ except (ValueError, TypeError):
+ signature = None
  if signature:
  argspec = str(signature)
  if realname == '<lambda>':

Misc/NEWS.d/next/Documentation/2020-05-03-00-47-47.bpo-39990.Qz_45W.rst

@@ -0,0 +1 @@
+Add option to resolve annotation strings when creating a inspect.Signature from function/callable.