aliles / funcsigs Goto Github PK

from funcsigs import signature
from functools import partial
f = partial(issubclass, bool)
signature(f)

yields

Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "C:\Miniconda3\envs\tools_py2\lib\site-packages\funcsigs\__init__.py", line 108, in signature
    sig = signature(obj.func)
  File "C:\Miniconda3\envs\tools_py2\lib\site-packages\funcsigs\__init__.py", line 185, in signature
    raise ValueError(msg)
ValueError: no signature found for builtin function <built-in function issubclass>

I recently updated to funcsigs 1.0 via the conda package manager and found that the documentation provided is for version 0.4.

I have a method like so:

class F:
def f(a, self):
pass

signature(partial(F.f, None)).bind(self=10)

fails, due to receiving self too many times.

The function bind() can't be defined with self as its own parameter - it conflicts with binds that pass self in. Instead it needs to take _args, *_kwargs, and pull self out of args[0].

I'll throw up a patch in alittle, for now (in mock), I'm monkeypatching to fix it.

Basically trying to pickle a signature pickle.dumps(signature(my_func)) leads to :

File "/usr/lib/python2.7/pickle.py", line 1374, in dumps
    Pickler(file, protocol).dump(obj)
  File "/usr/lib/python2.7/pickle.py", line 224, in dump
    self.save(obj)
  File "/usr/lib/python2.7/pickle.py", line 306, in save
    rv = reduce(self.proto)
  File "/usr/lib/python2.7/copy_reg.py", line 77, in _reduce_ex
    raise TypeError("a class that defines __slots__ without "
TypeError: a class that defines __slots__ without defining __getstate__ cannot be pickled

It would be useful to be able to serialize function signatures. Although I don't know what python 3.X does about this and if this is in the scope of funcsigs to implement this...

Currently it is not possible to install funcsigs using pip install.

The problem is caused by this line:
extras_require = {

     ':python_version<"2.7"': ['ordereddict'],
  },

error in funcsigs setup command: Invalid environment marker: python_version<"2.7"

Please remove the extra colon from the start of the string.

Hello, my name is Joel.
I've recently opened an issue in scikit-learn, and it turns out the issue has to do with funcsigs.

My question is:
Can the signature() method in funcsigs.py be used with a cython function (cyfunction object)?
As you can see in the other issue, I'm using python 2.7

Thanks!

http://bugs.python.org/issue23764 highlighted that one of the useful features inspect.signature offers over the old APIs is correctly following wrapper chains.

Python 3.4 split that feature out into an independently usable component: https://docs.python.org/3/library/inspect.html#inspect.unwrap

There are some other features potentially worth backporting from 3.4 (like the inspect.signature based inspect.getargspec and inspect.getfullargspec), so a full rebase may even be worthwhile.

Just thought I'd help other weary travelers.

Trying to run the tests directly (without using the coverage command) currently fails because unittest.begin() is not a valid method. This should be replaced with with unittest.main().

Fixing this (and running tests standalone) will break one of the formatannotation tests, as the expected result depends on how the tests are run.

<funcsigs.Signature object at 0x7fcc113c7dd0>, args = ('hello',), kwargs = {}, partial = False

    def _bind(self, args, kwargs, partial=False):
        '''Private method.  Don't use directly.'''
        arguments = OrderedDict()

        parameters = iter(self.parameters.values())
        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
            try:
                arg_val = next(arg_vals)
            except StopIteration:
                # No more positional arguments
                try:
                    param = next(parameters)
                except StopIteration:
                    # No more parameters. That's it. Just need to check that
                    # we have no `kwargs` after this while loop
                    break
                else:
                    if param.kind == _VAR_POSITIONAL:
                        # That's OK, just empty *args.  Let's start parsing
                        # kwargs
                        break
                    elif param.name in kwargs:
                        if param.kind == _POSITIONAL_ONLY:
                            msg = '{arg!r} parameter is positional only, ' \
                                  'but was passed as a keyword'
                            msg = msg.format(arg=param.name)
                            raise TypeError(msg)
                        parameters_ex = (param,)
                        break
                    elif (param.kind == _VAR_KEYWORD or
                                                param.default is not _empty):
                        # That's fine too - we have a default value for this
                        # parameter.  So, lets start parsing `kwargs`, starting
                        # with the current parameter
                        parameters_ex = (param,)
                        break
                    else:
                        if partial:
                            parameters_ex = (param,)
                            break
                        else:
                            msg = '{arg!r} parameter lacking default value'
                            msg = msg.format(arg=param.name)
                            raise TypeError(msg)
            else:
                # We have a positional argument to process
                try:
                    param = next(parameters)
                except StopIteration:
                    raise TypeError('too many positional arguments')
                else:
                    if param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY):
                        # Looks like we have no parameter for this positional
                        # argument
>                       raise TypeError('too many positional arguments')
E                       TypeError: too many positional arguments

changing the positional arguments to keyword arguments resolves this issue, but surely funcsigs should work with multiple positional arguments?

funcsigs.signature() treats unbound methods as any other method, despite m.self being None.

The attached pull requests adds a test case and fix. I've used a positional-only parameter because of this behaviour:

>>> class Test(object):
...     def method(self, *args, **kwargs):
...         return self, args, kwargs
...
>>> Test.method(Test())
(<__main__.Test object at 0x2c9fad0>, (), {})
>>> Test.method(self=Test())
Traceback (most recent call last):
  File "<input>", line 1, in <module>
TypeError: unbound method method() must be called with Test instance as first argument
 (got nothing instead)

I noticed that there is a disrepancy between the source on pypi.python.org and github.com. This is a little worrying, where is the source being version controlled if not here, the canonical source?

It links to https://github.com/alies/funcsigs/issues instead of https://github.com/aliles/funcsigs/issues

This is particularly a problem because the conda package manager won't allow you to use funcsigs 1.0 with python 2.7 because ordereddict cannot be installed for version 2.7. Setuptools fails with an error similar to this:

File "/home/user/miniconda3/pkgs/setuptools-20.2.2-py27_0/lib/python2.7/site-packages/setuptools-20.2.2-py2.7.egg/pkg_resources/init.py", line 2912, in
File "/home/user/miniconda3/pkgs/setuptools-20.2.2-py27_0/lib/python2.7/site-packages/setuptools-20.2.2-py2.7.egg/pkg_resources/init.py", line 2898, in _call_aside
File "/home/user/miniconda3/pkgs/setuptools-20.2.2-py27_0/lib/python2.7/site-packages/setuptools-20.2.2-py2.7.egg/pkg_resources/init.py", line 2925, in _initialize_master_working_set
File "/home/user/miniconda3/pkgs/setuptools-20.2.2-py27_0/lib/python2.7/site-packages/setuptools-20.2.2-py2.7.egg/pkg_resources/init.py", line 642, in _build_master
File "/home/user/miniconda3/pkgs/setuptools-20.2.2-py27_0/lib/python2.7/site-packages/setuptools-20.2.2-py2.7.egg/pkg_resources/init.py", line 943, in require
File "/home/user/miniconda3/pkgs/setuptools-20.2.2-py27_0/lib/python2.7/site-packages/setuptools-20.2.2-py2.7.egg/pkg_resources/init.py", line 830, in resolve
pkg_resources.DistributionNotFound: The 'ordereddict' distribution was not found and is required by funcsigs

Attempting to explicitly install ordereddict with the conda package manager fails like so:

-bash-4.2$ conda install ordereddict
Fetching package metadata: ....
Solving package specifications: .......
Error: Unsatisfiable package specifications.
Generating hint:
[ COMPLETE ]|################################################| 100%

Hint: the following packages conflict with each other:

• ordereddict
• python 2.7*

Use 'conda info ordereddict' etc. to see the dependencies for each package.

Presumably it should be possible to only require ordereddict for python versions < 2.6?

Hello :)

I'm using Sentry which uses Mock which uses this package.

I used to run pip wheel -r requirements.txt and then pip install --no-index --use-wheel --find-links=WHEEL_DIR -r requirements.txt and it worked fine for older versions. But now that this package emerged as a dependency, it no longer works.

I deleted the --no-index flag and the installation works for now. Would be good to skip the index though.

The issue URL on PyPI at https://pypi.python.org/pypi/funcsigs points to https://github.com/alies/funcsigs/issues, which is a 404.

It should be https://github.com/aliles/funcsigs/issues - note it's missing a single lowercase "L", which is kind of hard to spot.