How to find if python object is a function or class method?

user_208525 0
Viewed 165

Let's take this example:

class Foo:
   def func(self):
        pass

def func():
   pass

f1 = Foo.func
f2 = func

I'm inspecting code and want to find out from dir or inspect if f1 is a class method and f2 is a function that is not part of any class ?

python
3 Answers

Built-in inspect module has ismember and isfunction methods, https://docs.python.org/3/library/inspect.html

However, unless you're doing something rather esoteric, it should not matter for user code.

EDIT: And if you are doing something esoteric, note that in the original question you asked about the attribute on a class Foo, not on an instance of Foo. And that makes a difference:

In [1]: def f(): return None

In [2]: class F:
   ...:     def f(self):
   ...:         return None
   ...: 

In [3]: import inspect

In [4]: [inspect.isfunction(_) for _ in [f, F.f, F().f]]
Out[4]: [True, True, False]

In [5]: [inspect.ismethod(_) for _ in [f, F.f, F().f]]
Out[5]: [False, False, True]
user_1437650

at this moment the only thing I found is obj.__qualname__ - if it contains a dot - this means it's a method of the class

but I'm not 100% sure this is perfect solution

user_2085250

Just print the function names :

print('f1 =',f1)
print('f2 =',f2)

The output is :

f1 = <function Foo.func at 0x7f56105f3620>
f2 = <function func at 0x7f5611ce7e18>

This gives the full function names, including the parent class name if it is a class method as Foo.func

user_133281950
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