Python Get Function Docstring

Have you ever needed to quickly access a function's docstring in Python? The good news is that Python's built-in help() function provides us with a way to view docstrings easily, but there are some other helpful ways to fetch docstrings programmatically too.

__doc__ Attribute

Every Python function, module, and class comes with a built-in __doc__ attribute that contains its docstring. The easiest way to access a function's docstring is simply to call this attribute.

For example, let's say we have a function my_function:

def my_function(x, y):
    """ Returns the sum of two numbers """
    return x + y

To get the docstring of my_function, we can simply call its __doc__ attribute:

print(my_function.__doc__)

This will output:

Returns the sum of two numbers

Using inspect module

The inspect module provides several functions that can help us get the docstrings of most Python objects. For example, the getdoc() function returns the docstring of a given object.

To use getdoc(), you first need to import inspect:

import inspect

Let's say we have a class MyClass with a method my_method:

class MyClass:
    """ A simple class """

    def my_method(self):
        """ A simple method """
        pass

To get the docstring of my_method, we can use the getdoc() function from inspect:

print(inspect.getdoc(MyClass.my_method))

This will output:

A simple method

Conclusion

Knowing how to access a function's docstring programmatically can be a helpful tool when developing Python applications. The __doc__ attribute and the inspect module provide convenient ways to access a function's docstring. Keep in mind that docstrings are not only useful for developers, but also for other people using your code, as they provide valuable information on how your code works. So it's always a good idea to include them in your code!