python – How to get a function name as a string?

python – How to get a function name as a string?


Using __name__ is the preferred method as it applies uniformly. Unlike func_name, it works on built-in functions as well:

>>> import time
>>> time.time.func_name
Traceback (most recent call last):
  File <stdin>, line 1, in ?
AttributeError: builtin_function_or_method object has no attribute func_name
>>> time.time.__name__ 

Also the double underscores indicate to the reader this is a special attribute. As a bonus, classes and modules have a __name__ attribute too, so you only have remember one special name.

To get the current functions or methods name from inside it, consider:

import inspect

this_function_name = inspect.currentframe().f_code.co_name

sys._getframe also works instead of inspect.currentframe although the latter avoids accessing a private function.

To get the calling functions name instead, consider f_back as in inspect.currentframe().f_back.f_code.co_name.

If also using mypy, it can complain that:

error: Item None of Optional[FrameType] has no attribute f_code

To suppress the above error, consider:

import inspect
import types
from typing import cast

this_function_name = cast(types.FrameType, inspect.currentframe()).f_code.co_name

python – How to get a function name as a string?


There are also other fun properties of functions. Type dir(func_name) to list them. func_name.func_code.co_code is the compiled function, stored as a string.

import dis

will display the code in almost human readable format. 🙂

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