Replace _getargspec_py23() with inspect.getfullargspec().

scrapy/utils/python.py

@@ -180,23 +180,6 @@ def binary_is_text(data):
     return all(c not in _BINARYCHARS for c in data)
 
 
-def _getargspec_py23(func):
-    """_getargspec_py23(function) -> named tuple ArgSpec(args, varargs, keywords,
-                                                        defaults)
-
-    Was identical to inspect.getargspec() in python2, but uses
-    inspect.getfullargspec() for python3 behind the scenes to avoid
-    DeprecationWarning.
-
-    >>> def f(a, b=2, *ar, **kw):
-    ...     pass
-
-    >>> _getargspec_py23(f)
-    ArgSpec(args=['a', 'b'], varargs='ar', keywords='kw', defaults=(2,))
-    """
-    return inspect.ArgSpec(*inspect.getfullargspec(func)[:4])
-
-
 def get_func_args(func, stripself=False):
     """Return the argument name list of a callable"""
     if inspect.isfunction(func):
@@ -248,9 +231,9 @@ def get_spec(func):
     """
 
     if inspect.isfunction(func) or inspect.ismethod(func):
-        spec = _getargspec_py23(func)
+        spec = inspect.getfullargspec(func)
     elif hasattr(func, '__call__'):
-        spec = _getargspec_py23(func.__call__)
+        spec = inspect.getfullargspec(func.__call__)
     else:
         raise TypeError(f'{type(func)} is not callable')