Python Tutorial · Python Basics · Lesson 4 of 42
Python Comments
Explain your code with single-line comments and docstrings.
Single-line comments
A comment starts with #. Python ignores everything after it on that line.
# This is a comment
print("Hello") # comments can follow code too
# print("This line will not run")
Output
Hello
Multi-line comments
Python has no special multi-line comment syntax — use # on each line. You'll also see triple-quoted strings (""" ... """): when one is the first statement in a function, class or module it becomes a docstring, which documentation tools and help() can read.
def area(width, height):
"""Return the area of a rectangle."""
return width * height
print(area(3, 4))
print(area.__doc__)
Output
12 Return the area of a rectangle.
Good comments
Comment why something is done, not what the code obviously does. x = x + 1 # add one to x adds nothing; retries += 1 # the API is flaky on cold starts explains intent.
Test yourself
Which character starts a comment in Python?
//#--/*
Show answer
Answer: #