| # Copyright 2001-2013 Python Software Foundation; All Rights Reserved |
| """Function signature objects for callables |
| |
| Back port of Python 3.3's function signature tools from the inspect module, |
| modified to be compatible with Python 2.6, 2.7 and 3.2+. |
| """ |
| from __future__ import absolute_import, division, print_function |
| import itertools |
| import functools |
| import re |
| import types |
| |
| try: |
| from collections import OrderedDict |
| except ImportError: |
| from funcsigs.odict import OrderedDict |
| |
| from funcsigs.version import __version__ |
| |
| __all__ = ['BoundArguments', 'Parameter', 'Signature', 'signature'] |
| |
| |
| _WrapperDescriptor = type(type.__call__) |
| _MethodWrapper = type(all.__call__) |
| |
| _NonUserDefinedCallables = (_WrapperDescriptor, |
| _MethodWrapper, |
| types.BuiltinFunctionType) |
| |
| |
| def formatannotation(annotation, base_module=None): |
| if isinstance(annotation, type): |
| if annotation.__module__ in ('builtins', '__builtin__', base_module): |
| return annotation.__name__ |
| return annotation.__module__+'.'+annotation.__name__ |
| return repr(annotation) |
| |
| |
| def _get_user_defined_method(cls, method_name, *nested): |
| try: |
| if cls is type: |
| return |
| meth = getattr(cls, method_name) |
| for name in nested: |
| meth = getattr(meth, name, meth) |
| except AttributeError: |
| return |
| else: |
| if not isinstance(meth, _NonUserDefinedCallables): |
| # Once '__signature__' will be added to 'C'-level |
| # callables, this check won't be necessary |
| return meth |
| |
| |
| def signature(obj): |
| '''Get a signature object for the passed callable.''' |
| |
| if not callable(obj): |
| raise TypeError('{0!r} is not a callable object'.format(obj)) |
| |
| if isinstance(obj, types.MethodType): |
| sig = signature(obj.__func__) |
| if obj.__self__ is None: |
| # Unbound method: the first parameter becomes positional-only |
| if sig.parameters: |
| first = sig.parameters.values()[0].replace( |
| kind=_POSITIONAL_ONLY) |
| return sig.replace( |
| parameters=(first,) + tuple(sig.parameters.values())[1:]) |
| else: |
| return sig |
| else: |
| # In this case we skip the first parameter of the underlying |
| # function (usually `self` or `cls`). |
| return sig.replace(parameters=tuple(sig.parameters.values())[1:]) |
| |
| try: |
| sig = obj.__signature__ |
| except AttributeError: |
| pass |
| else: |
| if sig is not None: |
| return sig |
| |
| try: |
| # Was this function wrapped by a decorator? |
| wrapped = obj.__wrapped__ |
| except AttributeError: |
| pass |
| else: |
| return signature(wrapped) |
| |
| if isinstance(obj, types.FunctionType): |
| return Signature.from_function(obj) |
| |
| if isinstance(obj, functools.partial): |
| sig = signature(obj.func) |
| |
| new_params = OrderedDict(sig.parameters.items()) |
| |
| partial_args = obj.args or () |
| partial_keywords = obj.keywords or {} |
| try: |
| ba = sig.bind_partial(*partial_args, **partial_keywords) |
| except TypeError as ex: |
| msg = 'partial object {0!r} has incorrect arguments'.format(obj) |
| raise ValueError(msg) |
| |
| 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) |
| |
| return sig.replace(parameters=new_params.values()) |
| |
| sig = None |
| if isinstance(obj, type): |
| # obj is a class or a metaclass |
| |
| # First, let's see if it has an overloaded __call__ defined |
| # in its metaclass |
| call = _get_user_defined_method(type(obj), '__call__') |
| if call is not None: |
| sig = signature(call) |
| else: |
| # Now we check if the 'obj' class has a '__new__' method |
| new = _get_user_defined_method(obj, '__new__') |
| if new is not None: |
| sig = signature(new) |
| else: |
| # Finally, we should have at least __init__ implemented |
| init = _get_user_defined_method(obj, '__init__') |
| if init is not None: |
| sig = signature(init) |
| elif not isinstance(obj, _NonUserDefinedCallables): |
| # An object with __call__ |
| # We also check that the 'obj' is not an instance of |
| # _WrapperDescriptor or _MethodWrapper to avoid |
| # infinite recursion (and even potential segfault) |
| call = _get_user_defined_method(type(obj), '__call__', 'im_func') |
| if call is not None: |
| sig = signature(call) |
| |
| if sig is not None: |
| # For classes and objects we skip the first parameter of their |
| # __call__, __new__, or __init__ methods |
| return sig.replace(parameters=tuple(sig.parameters.values())[1:]) |
| |
| if isinstance(obj, types.BuiltinFunctionType): |
| # Raise a nicer error message for builtins |
| msg = 'no signature found for builtin function {0!r}'.format(obj) |
| raise ValueError(msg) |
| |
| raise ValueError('callable {0!r} is not supported by signature'.format(obj)) |
| |
| |
| class _void(object): |
| '''A private marker - used in Parameter & Signature''' |
| |
| |
| class _empty(object): |
| pass |
| |
| |
| class _ParameterKind(int): |
| def __new__(self, *args, **kwargs): |
| obj = int.__new__(self, *args) |
| obj._name = kwargs['name'] |
| return obj |
| |
| def __str__(self): |
| return self._name |
| |
| def __repr__(self): |
| return '<_ParameterKind: {0!r}>'.format(self._name) |
| |
| |
| _POSITIONAL_ONLY = _ParameterKind(0, name='POSITIONAL_ONLY') |
| _POSITIONAL_OR_KEYWORD = _ParameterKind(1, name='POSITIONAL_OR_KEYWORD') |
| _VAR_POSITIONAL = _ParameterKind(2, name='VAR_POSITIONAL') |
| _KEYWORD_ONLY = _ParameterKind(3, name='KEYWORD_ONLY') |
| _VAR_KEYWORD = _ParameterKind(4, name='VAR_KEYWORD') |
| |
| |
| class Parameter(object): |
| '''Represents a parameter in a function signature. |
| |
| Has the following public attributes: |
| |
| * name : str |
| The name of the parameter as a string. |
| * default : object |
| The default value for the parameter if specified. If the |
| parameter has no default value, this attribute is not set. |
| * annotation |
| The annotation for the parameter if specified. If the |
| parameter has no annotation, this attribute is not set. |
| * kind : str |
| Describes how argument values are bound to the parameter. |
| Possible values: `Parameter.POSITIONAL_ONLY`, |
| `Parameter.POSITIONAL_OR_KEYWORD`, `Parameter.VAR_POSITIONAL`, |
| `Parameter.KEYWORD_ONLY`, `Parameter.VAR_KEYWORD`. |
| ''' |
| |
| __slots__ = ('_name', '_kind', '_default', '_annotation', '_partial_kwarg') |
| |
| POSITIONAL_ONLY = _POSITIONAL_ONLY |
| POSITIONAL_OR_KEYWORD = _POSITIONAL_OR_KEYWORD |
| VAR_POSITIONAL = _VAR_POSITIONAL |
| KEYWORD_ONLY = _KEYWORD_ONLY |
| VAR_KEYWORD = _VAR_KEYWORD |
| |
| empty = _empty |
| |
| def __init__(self, name, kind, default=_empty, annotation=_empty, |
| _partial_kwarg=False): |
| |
| if kind not in (_POSITIONAL_ONLY, _POSITIONAL_OR_KEYWORD, |
| _VAR_POSITIONAL, _KEYWORD_ONLY, _VAR_KEYWORD): |
| raise ValueError("invalid value for 'Parameter.kind' attribute") |
| self._kind = kind |
| |
| if default is not _empty: |
| if kind in (_VAR_POSITIONAL, _VAR_KEYWORD): |
| msg = '{0} parameters cannot have default values'.format(kind) |
| raise ValueError(msg) |
| self._default = default |
| self._annotation = annotation |
| |
| if name is None: |
| if kind != _POSITIONAL_ONLY: |
| raise ValueError("None is not a valid name for a " |
| "non-positional-only parameter") |
| self._name = name |
| else: |
| name = str(name) |
| if kind != _POSITIONAL_ONLY and not re.match(r'[a-z_]\w*$', name, re.I): |
| msg = '{0!r} is not a valid parameter name'.format(name) |
| raise ValueError(msg) |
| self._name = name |
| |
| self._partial_kwarg = _partial_kwarg |
| |
| @property |
| def name(self): |
| return self._name |
| |
| @property |
| def default(self): |
| return self._default |
| |
| @property |
| def annotation(self): |
| return self._annotation |
| |
| @property |
| def kind(self): |
| return self._kind |
| |
| def replace(self, name=_void, kind=_void, annotation=_void, |
| default=_void, _partial_kwarg=_void): |
| '''Creates a customized copy of the Parameter.''' |
| |
| if name is _void: |
| name = self._name |
| |
| if kind is _void: |
| kind = self._kind |
| |
| if annotation is _void: |
| annotation = self._annotation |
| |
| 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) |
| |
| def __str__(self): |
| kind = self.kind |
| |
| formatted = self._name |
| if kind == _POSITIONAL_ONLY: |
| if formatted is None: |
| formatted = '' |
| formatted = '<{0}>'.format(formatted) |
| |
| # Add annotation and default value |
| if self._annotation is not _empty: |
| formatted = '{0}:{1}'.format(formatted, |
| formatannotation(self._annotation)) |
| |
| if self._default is not _empty: |
| formatted = '{0}={1}'.format(formatted, repr(self._default)) |
| |
| if kind == _VAR_POSITIONAL: |
| formatted = '*' + formatted |
| elif kind == _VAR_KEYWORD: |
| formatted = '**' + formatted |
| |
| return formatted |
| |
| def __repr__(self): |
| return '<{0} at {1:#x} {2!r}>'.format(self.__class__.__name__, |
| id(self), self.name) |
| |
| def __hash__(self): |
| msg = "unhashable type: '{0}'".format(self.__class__.__name__) |
| raise TypeError(msg) |
| |
| def __eq__(self, other): |
| return (issubclass(other.__class__, Parameter) and |
| self._name == other._name and |
| self._kind == other._kind and |
| self._default == other._default and |
| self._annotation == other._annotation) |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| |
| |
| class BoundArguments(object): |
| '''Result of `Signature.bind` call. Holds the mapping of arguments |
| to the function's parameters. |
| |
| Has the following public attributes: |
| |
| * arguments : OrderedDict |
| An ordered mutable mapping of parameters' names to arguments' values. |
| Does not contain arguments' default values. |
| * signature : Signature |
| The Signature object that created this instance. |
| * args : tuple |
| Tuple of positional arguments values. |
| * kwargs : dict |
| Dict of keyword arguments values. |
| ''' |
| |
| def __init__(self, signature, arguments): |
| self.arguments = arguments |
| self._signature = signature |
| |
| @property |
| def signature(self): |
| return self._signature |
| |
| @property |
| 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 |
| break |
| |
| try: |
| arg = self.arguments[param_name] |
| except KeyError: |
| # We're done here. Other arguments |
| # will be mapped in 'BoundArguments.kwargs' |
| break |
| else: |
| if param.kind == _VAR_POSITIONAL: |
| # *args |
| args.extend(arg) |
| else: |
| # plain argument |
| args.append(arg) |
| |
| return tuple(args) |
| |
| @property |
| def kwargs(self): |
| kwargs = {} |
| 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): |
| kwargs_started = True |
| else: |
| if param_name not in self.arguments: |
| kwargs_started = True |
| continue |
| |
| if not kwargs_started: |
| continue |
| |
| try: |
| arg = self.arguments[param_name] |
| except KeyError: |
| pass |
| else: |
| if param.kind == _VAR_KEYWORD: |
| # **kwargs |
| kwargs.update(arg) |
| else: |
| # plain keyword argument |
| kwargs[param_name] = arg |
| |
| return kwargs |
| |
| def __hash__(self): |
| msg = "unhashable type: '{0}'".format(self.__class__.__name__) |
| raise TypeError(msg) |
| |
| def __eq__(self, other): |
| return (issubclass(other.__class__, BoundArguments) and |
| self.signature == other.signature and |
| self.arguments == other.arguments) |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| |
| |
| class Signature(object): |
| '''A Signature object represents the overall signature of a function. |
| It stores a Parameter object for each parameter accepted by the |
| function, as well as information specific to the function itself. |
| |
| A Signature object has the following public attributes and methods: |
| |
| * parameters : OrderedDict |
| An ordered mapping of parameters' names to the corresponding |
| Parameter objects (keyword-only arguments are in the same order |
| as listed in `code.co_varnames`). |
| * return_annotation : object |
| The annotation for the return type of the function if specified. |
| If the function has no annotation for its return type, this |
| attribute is not set. |
| * bind(*args, **kwargs) -> BoundArguments |
| Creates a mapping from positional and keyword arguments to |
| parameters. |
| * bind_partial(*args, **kwargs) -> BoundArguments |
| Creates a partial mapping from positional and keyword arguments |
| to parameters (simulating 'functools.partial' behavior.) |
| ''' |
| |
| __slots__ = ('_return_annotation', '_parameters') |
| |
| _parameter_cls = Parameter |
| _bound_arguments_cls = BoundArguments |
| |
| empty = _empty |
| |
| def __init__(self, parameters=None, return_annotation=_empty, |
| __validate_parameters__=True): |
| '''Constructs Signature from the given list of Parameter |
| objects and 'return_annotation'. All arguments are optional. |
| ''' |
| |
| if parameters is None: |
| params = OrderedDict() |
| else: |
| if __validate_parameters__: |
| params = OrderedDict() |
| top_kind = _POSITIONAL_ONLY |
| |
| for idx, param in enumerate(parameters): |
| kind = param.kind |
| if kind < top_kind: |
| msg = 'wrong parameter order: {0} before {1}' |
| msg = msg.format(top_kind, param.kind) |
| raise ValueError(msg) |
| else: |
| top_kind = kind |
| |
| name = param.name |
| if name is None: |
| name = str(idx) |
| param = param.replace(name=name) |
| |
| if name in params: |
| msg = 'duplicate parameter name: {0!r}'.format(name) |
| raise ValueError(msg) |
| params[name] = param |
| else: |
| params = OrderedDict(((param.name, param) |
| for param in parameters)) |
| |
| self._parameters = params |
| self._return_annotation = return_annotation |
| |
| @classmethod |
| def from_function(cls, func): |
| '''Constructs Signature for the given python function''' |
| |
| if not isinstance(func, types.FunctionType): |
| raise TypeError('{0!r} is not a Python function'.format(func)) |
| |
| Parameter = cls._parameter_cls |
| |
| # Parameter information. |
| func_code = func.__code__ |
| pos_count = func_code.co_argcount |
| arg_names = func_code.co_varnames |
| positional = tuple(arg_names[:pos_count]) |
| keyword_only_count = getattr(func_code, 'co_kwonlyargcount', 0) |
| keyword_only = arg_names[pos_count:(pos_count + keyword_only_count)] |
| annotations = getattr(func, '__annotations__', {}) |
| defaults = func.__defaults__ |
| kwdefaults = getattr(func, '__kwdefaults__', None) |
| |
| if defaults: |
| pos_default_count = len(defaults) |
| else: |
| pos_default_count = 0 |
| |
| parameters = [] |
| |
| # Non-keyword-only parameters w/o defaults. |
| non_default_count = pos_count - pos_default_count |
| for name in positional[:non_default_count]: |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_POSITIONAL_OR_KEYWORD)) |
| |
| # ... w/ defaults. |
| for offset, name in enumerate(positional[non_default_count:]): |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_POSITIONAL_OR_KEYWORD, |
| default=defaults[offset])) |
| |
| # *args |
| if func_code.co_flags & 0x04: |
| name = arg_names[pos_count + keyword_only_count] |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_VAR_POSITIONAL)) |
| |
| # Keyword-only parameters. |
| for name in keyword_only: |
| default = _empty |
| if kwdefaults is not None: |
| default = kwdefaults.get(name, _empty) |
| |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_KEYWORD_ONLY, |
| default=default)) |
| # **kwargs |
| if func_code.co_flags & 0x08: |
| index = pos_count + keyword_only_count |
| if func_code.co_flags & 0x04: |
| index += 1 |
| |
| name = arg_names[index] |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_VAR_KEYWORD)) |
| |
| return cls(parameters, |
| return_annotation=annotations.get('return', _empty), |
| __validate_parameters__=False) |
| |
| @property |
| def parameters(self): |
| try: |
| return types.MappingProxyType(self._parameters) |
| except AttributeError: |
| return OrderedDict(self._parameters.items()) |
| |
| @property |
| def return_annotation(self): |
| return self._return_annotation |
| |
| def replace(self, parameters=_void, return_annotation=_void): |
| '''Creates a customized copy of the Signature. |
| Pass 'parameters' and/or 'return_annotation' arguments |
| to override them in the new copy. |
| ''' |
| |
| if parameters is _void: |
| parameters = self.parameters.values() |
| |
| if return_annotation is _void: |
| return_annotation = self._return_annotation |
| |
| return type(self)(parameters, |
| return_annotation=return_annotation) |
| |
| def __hash__(self): |
| msg = "unhashable type: '{0}'".format(self.__class__.__name__) |
| raise TypeError(msg) |
| |
| def __eq__(self, other): |
| if (not issubclass(type(other), Signature) or |
| self.return_annotation != other.return_annotation or |
| len(self.parameters) != len(other.parameters)): |
| return False |
| |
| other_positions = dict((param, idx) |
| for idx, param in enumerate(other.parameters.keys())) |
| |
| for idx, (param_name, param) in enumerate(self.parameters.items()): |
| if param.kind == _KEYWORD_ONLY: |
| try: |
| other_param = other.parameters[param_name] |
| except KeyError: |
| return False |
| else: |
| if param != other_param: |
| return False |
| else: |
| try: |
| other_idx = other_positions[param_name] |
| except KeyError: |
| return False |
| else: |
| if (idx != other_idx or |
| param != other.parameters[param_name]): |
| return False |
| |
| return True |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| |
| 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') |
| |
| if param.kind == _VAR_POSITIONAL: |
| # We have an '*args'-like argument, let's fill it with |
| # all positional arguments we have left and move on to |
| # the next phase |
| values = [arg_val] |
| values.extend(arg_vals) |
| arguments[param.name] = tuple(values) |
| break |
| |
| if param.name in kwargs: |
| raise TypeError('multiple values for argument ' |
| '{arg!r}'.format(arg=param.name)) |
| |
| arguments[param.name] = arg_val |
| |
| # Now, we iterate through the remaining parameters to process |
| # keyword arguments |
| kwargs_param = None |
| for param in itertools.chain(parameters_ex, parameters): |
| if param.kind == _POSITIONAL_ONLY: |
| # This should never happen in case of a properly built |
| # Signature object (but let's have this check here |
| # to ensure correct behaviour just in case) |
| raise TypeError('{arg!r} parameter is positional only, ' |
| 'but was passed as a keyword'. \ |
| format(arg=param.name)) |
| |
| if param.kind == _VAR_KEYWORD: |
| # Memorize that we have a '**kwargs'-like parameter |
| kwargs_param = param |
| continue |
| |
| param_name = param.name |
| try: |
| arg_val = kwargs.pop(param_name) |
| except KeyError: |
| # We have no value for this parameter. It's fine though, |
| # if it has a default value, or it is an '*args'-like |
| # parameter, left alone by the processing of positional |
| # arguments. |
| if (not partial and param.kind != _VAR_POSITIONAL and |
| param.default is _empty): |
| raise TypeError('{arg!r} parameter lacking default value'. \ |
| format(arg=param_name)) |
| |
| else: |
| arguments[param_name] = arg_val |
| |
| if kwargs: |
| if kwargs_param is not None: |
| # Process our '**kwargs'-like parameter |
| arguments[kwargs_param.name] = kwargs |
| else: |
| raise TypeError('too many keyword arguments') |
| |
| return self._bound_arguments_cls(self, arguments) |
| |
| def bind(self, *args, **kwargs): |
| '''Get a BoundArguments object, that maps the passed `args` |
| and `kwargs` to the function's signature. Raises `TypeError` |
| if the passed arguments can not be bound. |
| ''' |
| return self._bind(args, kwargs) |
| |
| def bind_partial(self, *args, **kwargs): |
| '''Get a BoundArguments object, that partially maps the |
| passed `args` and `kwargs` to the function's signature. |
| Raises `TypeError` if the passed arguments can not be bound. |
| ''' |
| return self._bind(args, kwargs, partial=True) |
| |
| def __str__(self): |
| result = [] |
| render_kw_only_separator = True |
| for idx, param in enumerate(self.parameters.values()): |
| formatted = str(param) |
| |
| kind = param.kind |
| if kind == _VAR_POSITIONAL: |
| # OK, we have an '*args'-like parameter, so we won't need |
| # a '*' to separate keyword-only arguments |
| render_kw_only_separator = False |
| elif kind == _KEYWORD_ONLY and render_kw_only_separator: |
| # We have a keyword-only parameter to render and we haven't |
| # rendered an '*args'-like parameter before, so add a '*' |
| # separator to the parameters list ("foo(arg1, *, arg2)" case) |
| result.append('*') |
| # This condition should be only triggered once, so |
| # reset the flag |
| render_kw_only_separator = False |
| |
| result.append(formatted) |
| |
| rendered = '({0})'.format(', '.join(result)) |
| |
| if self.return_annotation is not _empty: |
| anno = formatannotation(self.return_annotation) |
| rendered += ' -> {0}'.format(anno) |
| |
| return rendered |
