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Currently, static methods created by the @staticmethod decorator are not callable as regular function. Example:
---
@staticmethod
def func():
 print("my func")
class MyClass:
 method = func
func() # A: regular function
MyClass.method() # B: class method
MyClass().method() # C: instance method
---
The func() call raises TypeError('staticmethod' object is not callable) exception.
I propose to make staticmethod objects callable to get a similar to built-in function:
---
func = len
class MyClass:
 method = func
func("abc") # A: regular function
MyClass.method("abc") # B: class method
MyClass().method("abc") # C: instance method
---
The 3 variants (A, B, C) to call the built-in len() function work just as expected.
If static method objects become callable, the 3 variants (A, B, C) will just work.
It would avoid the hack like _pyio.Wrapper:
---
class DocDescriptor:
 """Helper for builtins.open.__doc__
 """
 def __get__(self, obj, typ=None):
 return (
 "open(file, mode='r', buffering=-1, encoding=None, "
 "errors=None, newline=None, closefd=True)\n\n" +
 open.__doc__)
class OpenWrapper:
 """Wrapper for builtins.open
 Trick so that open won't become a bound method when stored
 as a class variable (as dbm.dumb does).
 See initstdio() in Python/pylifecycle.c.
 """
 __doc__ = DocDescriptor()
 def __new__(cls, *args, **kwargs):
 return open(*args, **kwargs)
---
Currently, it's not possible possible to use directly _pyio.open as a method:
---
class MyClass:
 method = _pyio.open
---
whereas "method = io.open" just works because io.open() is a built-in function.
See also bpo-43680 "Remove undocumented io.OpenWrapper and _pyio.OpenWrapper" and my thread on python-dev:
"Weird io.OpenWrapper hack to use a function as method"
https://mail.python.org/archives/list/python-dev@python.org/thread/QZ7SFW3IW3S2C5RMRJZOOUFSHHUINNME/