Python Docstring

What is Python Docstring?

Python docstring or Documentation strings is a string literally used in the class, module, function, or method definition.

As like multiline comment, docstring is also declared using three (‘’’) or four (“””). For example

‘’’ triple single quotes ‘’’ or “”” triple double quotes ”””

Docstrings are accessible from the doc attribute (__doc__) for any of the Python objects and built-in functions. Docstrings are great for understanding the functionality of the more extensive code of the project.

Example of Code:

def addition(n):
		''' This is a docstrings example we have added in addition function '''
		return n+n

print(addition.__doc__)

To run this docstring code, we have to follow this step.

print(addition.__doc__)

Here the output of string literal.

Output

	This is a docstrings example we have added in the addition function. 

Here, we have documented our addition function, and then we are accessing it with __doc__ attribute.

Docstring in built-in functions

Now let’s use docstring for the built-in python function and let it have a print function, for example.

print(print.__doc__)

Output:

print(value, ..., sep=' ', end='\n', file=sys.stdout, flush=False)

Prints the values to a stream, or to sys.stdout by default.
Optional keyword arguments:
file:  a file-like object (stream); defaults to the current sys.stdout.
sep:   string inserted between values, default a space.
end:   string appended after the last value, default a newline.
flush: whether to forcibly flush the stream.

As we can see, we got the documentation output of the print() function defined by python.

Docstring in Python Module

import numpy 
print(numpy.__doc__)

Output

NumPy
=====

Provides
  1. An array object of arbitrary homogeneous items
  2. Fast mathematical operations over arrays
  3. Linear Algebra, Fourier Transforms, Random Number Generation

How to use the documentation
----------------------------
Documentation is available in two forms: docstrings provided
with the code, and a loose standing reference guide, available from
`the NumPy homepage <https://www.scipy.org>`_.

We recommend exploring the docstrings using
`IPython <https://ipython.org>`_, an advanced Python shell with
TAB-completion and introspection capabilities.  See below for further
instructions.

The docstring examples assume that `numpy` has been imported as `np`::

  >>> import numpy as np

.
.
.
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