178 – Remove indentation from multiline strings

When you define a multiline string, you naturally get the indentation of the code that surrounds your string:

if show_instructions:
    instructions = """
        Instructions:
        Write Python.
    """
    print("Hey!")
    print(instructions)

Hey!

        Instructions:
        Write Python.

The instructions are indented because of the leading whitespace associated with the indentation of the if block they were defined in.

One way to fix this issue would be by deleting the indentation from the string yourself:

if show_instructions:
    instructions = """
Instructions:
Write Python.
"""
    print("Hey!")
    print(instructions)

Hey!

Instructions:
Write Python.

The problem with this solution is that the dedentend string breaks the flow of the code and makes it harder to understand the hierarchy of the code blocks.

A better fix for the indentation issue uses textwrap.dedent:

from textwrap import dedent

if show_instructions:
    instructions = dedent(
        """
        Instructions:
        Write Python.
        """
    )
    print("Hey!")
    print(instructions)

Hey!

Instructions:
Write Python.

dedent figures out how much indentation leading indentation is common to every line and removes it, allowing you to define multiline strings more conveniently.