def update_wrapper(
wrapper: T.Callable,
wrapped: T.Callable,
signature: T.Union[_FullerSig, None, bool] = True, # not in functools
docstring: T.Union[str, bool] = True, # not in functools
assigned: T.Sequence[str] = WRAPPER_ASSIGNMENTS,
updated: T.Sequence[str] = WRAPPER_UPDATES,
# docstring options
_doc_fmt: T.Optional[dict] = None, # not in functools
_doc_style: T.Union[str, T.Callable, None] = None,
):
"""Update a wrapper function to look like the wrapped function.
Parameters
----------
wrapper : Callable
the function to be updated
wrapped : Callable
the original function
signature : Signature or None or bool, optional
signature to impose on `wrapper`.
None and False default to `wrapped`'s signature.
True merges `wrapper` and `wrapped` kwdefaults & annotations
docstring : str or bool, optional
docstring to impose on `wrapper`.
False ignores `wrapper`'s docstring, using only `wrapped`'s docstring.
None (defualt) merges the `wrapper` and `wrapped` docstring
assigned : tuple, optional
tuple naming the attributes assigned directly
from the wrapped function to the wrapper function (defaults to
``functools.WRAPPER_ASSIGNMENTS``)
updated : tuple, optional
is a tuple naming the attributes of the wrapper that
are updated with the corresponding attribute from the wrapped
function (defaults to ``functools.WRAPPER_UPDATES``)
_doc_fmt : dict, optional
dictionary to format wrapper docstring
_doc_style: str or Callable, optional
the style of the docstring
if None (default), appends `wrapper` docstring
if str or Callable, merges the docstring
Returns
-------
wrapper : Callable
`wrapper` function updated by the `wrapped` function's attributes and
also the provided `signature` and `docstring`.
Raises
------
ValueError
if docstring is True
"""
# ---------------------------------------
# preamble
signature, _update_sig = __parse_sig_for_update_wrapper(signature, wrapped)
# need to get wrapper properties now
wrapper_sig = _FullerSig.from_callable(wrapper)
wrapper_doc = _nspct.getdoc(wrapper) or ""
wrapper_doc = "\n".join(wrapper_doc.split("\n")[1:]) # drop title
if _doc_fmt is None:
_doc_fmt = {}
# ---------------------------------------
# update wrapper (same as functools.update_wrapper)
for attr in assigned:
try:
value = getattr(wrapped, attr)
except AttributeError:
pass
else:
setattr(wrapper, attr, value)
for attr in updated: # update whole dictionary
getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
# ---------------------------------------
# deal with signature
if signature in (None, False):
pass
elif _update_sig: # merge wrapped and wrapper signature
signature = __update_wrapper_update_sig(
signature, wrapper_sig, _doc_fmt
)
for attr in SIGNATURE_ASSIGNMENTS:
value = getattr(signature, attr)
setattr(wrapper, attr, value)
wrapper.__signature__ = signature.signature
else: # a signature object
for attr in SIGNATURE_ASSIGNMENTS:
_value = getattr(signature, attr)
setattr(wrapper, attr, _value)
# for docstring
for param in wrapper_sig.parameters.values():
# can only merge keyword-only
if param.kind == _nspct.KEYWORD_ONLY:
_doc_fmt[param.name] = param.default
wrapper.__signature__ = signature.signature
# ---------------------------------------
# docstring
if _doc_fmt: # (not empty dict)
wrapper_doc = _FormatTemplate(wrapper_doc).safe_substitute(**_doc_fmt)
wrapper.__doc__ = __update_wrapper_docstring(
wrapped,
docstring=docstring,
wrapper_doc=wrapper_doc,
_doc_style=_doc_style,
)
# Issue #17482: set __wrapped__ last so we don't inadvertently copy it
# from the wrapped function when updating __dict__
wrapper.__wrapped__ = wrapped
# Return the wrapper so this can be used as a decorator via partial()
return wrapper
