Python example to print the function name as string with __name__ and __qualname__

How to get the function name as string:

In this post, we will learn how to get the name of a function as string in Python. Python provides an easy way to get the function name. Python provides two attributes called __name__ and __qualname__ to get the name of a function in string format. Let’s learn how to read these attributes with examples.

How to use the __name__ attribute to read a function name in Python:

The __name__ attribute is available for each function in Python. We can use the function name and .__name__ to get the name of that function. Let’s try this with an example:

def first_function():
    print('Hello from first_function')

def second_function():
    print('Hello from second_function')

print(first_function.__name__)
print(second_function.__name__)

If you run this program, it will print the names of the functions first_function and second_function:

$ python3 example.py
first_function
second_function

Type of __name__:

Let’s check the type of the valur returned by __name__. We can use the type() method to get that:

def first_function():
    print('Hello from first_function')

print(type(first_function.__name__))

It will print the type of first_function.__name__:

<class 'str'>

__name__ with system modules:

We can use __name__ with system modules or any other modules as well. It will return the name of that module:

import os
import random

print(os.__name__)
print(random.__name__)

It will print:

os
random

How to read the __qualname__ attribute to read a function name:

Python provides one more attribute called __qualname__ to read a function name. It is also called as qualified name. Note that it is available since Python 3.3.

def first_function():
    print('Hello from first_function')

print(first_function.__qualname__)

It will print:

first_function

__qualname__ is better than __name__ if you use it for debugging purpose. Let’s take a look at the below example:

class Parent:
    def print_hello():
        print('Hello')
    class Child:
        def print_hello():
            print('Hello')

print(Parent.print_hello.__name__)
print(Parent.Child.print_hello.__name__)

This is printing the name of the print_hello methods of the Parent and Child classes. But since the name is not different of these methods, it will print the same for both:

print_hello
print_hello

Now, let’s try it with __qualname__:

class Parent:
    def print_hello():
        print('Hello')
    class Child:
        def print_hello():
            print('Hello')

print(Parent.print_hello.__qualname__)
print(Parent.Child.print_hello.__qualname__)

It will print the full path with the name:

Parent.print_hello
Parent.Child.print_hello

So, if you want to use these attributes for logging, __qualname__ will give a better result.

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