from __future__ import absolute_import import inspect from django.utils import six def getargspec(func): if six.PY2: return inspect.getargspec(func) sig = inspect.signature(func) args = [ p.name for p in sig.parameters.values() if p.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD ] varargs = [ p.name for p in sig.parameters.values() if p.kind == inspect.Parameter.VAR_POSITIONAL ] varargs = varargs[0] if varargs else None varkw = [ p.name for p in sig.parameters.values() if p.kind == inspect.Parameter.VAR_KEYWORD ] varkw = varkw[0] if varkw else None defaults = [ p.default for p in sig.parameters.values() if p.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD and p.default is not p.empty ] or None return args, varargs, varkw, defaults def get_func_args(func): if six.PY2: argspec = inspect.getargspec(func) return argspec.args[1:] # ignore 'self' sig = inspect.signature(func) return [ arg_name for arg_name, param in sig.parameters.items() if param.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD ] def get_func_full_args(func): """ Return a list of (argument name, default value) tuples. If the argument does not have a default value, omit it in the tuple. Arguments such as *args and **kwargs are also included. """ if six.PY2: argspec = inspect.getargspec(func) args = argspec.args[1:] # ignore 'self' defaults = argspec.defaults or [] # Split args into two lists depending on whether they have default value no_default = args[:len(args) - len(defaults)] with_default = args[len(args) - len(defaults):] # Join the two lists and combine it with default values args = [(arg,) for arg in no_default] + zip(with_default, defaults) # Add possible *args and **kwargs and prepend them with '*' or '**' varargs = [('*' + argspec.varargs,)] if argspec.varargs else [] kwargs = [('**' + argspec.keywords,)] if argspec.keywords else [] return args + varargs + kwargs sig = inspect.signature(func) args = [] for arg_name, param in sig.parameters.items(): name = arg_name # Ignore 'self' if name == 'self': continue if param.kind == inspect.Parameter.VAR_POSITIONAL: name = '*' + name elif param.kind == inspect.Parameter.VAR_KEYWORD: name = '**' + name if param.default != inspect.Parameter.empty: args.append((name, param.default)) else: args.append((name,)) return args def func_accepts_kwargs(func): if six.PY2: # Not all callables are inspectable with getargspec, so we'll # try a couple different ways but in the end fall back on assuming # it is -- we don't want to prevent registration of valid but weird # callables. try: argspec = inspect.getargspec(func) except TypeError: try: argspec = inspect.getargspec(func.__call__) except (TypeError, AttributeError): argspec = None return not argspec or argspec[2] is not None return any( p for p in inspect.signature(func).parameters.values() if p.kind == p.VAR_KEYWORD ) def func_accepts_var_args(func): """ Return True if function 'func' accepts positional arguments *args. """ if six.PY2: return inspect.getargspec(func)[1] is not None return any( p for p in inspect.signature(func).parameters.values() if p.kind == p.VAR_POSITIONAL ) def func_has_no_args(func): args = inspect.getargspec(func)[0] if six.PY2 else [ p for p in inspect.signature(func).parameters.values() if p.kind == p.POSITIONAL_OR_KEYWORD ] return len(args) == 1 def func_supports_parameter(func, parameter): if six.PY3: return parameter in inspect.signature(func).parameters else: args, varargs, varkw, defaults = inspect.getargspec(func) return parameter in args