How Does Indentation Affect Python Code and What Are Common Indentation Errors?

Indentation in Python

Python is a programming language that uses indentation to define code blocks. This means that spaces or tabs are used to indicate the start and end of loops, conditional statements, and functions. The number of spaces or tabs used to indent code is essential, as incorrect indentation can lead to errors.

Common Indentation Errors

IndentationError: unexpected indent

This error occurs when a statement is indented unnecessarily or incorrectly. For example, indenting a statement that is not part of a code block.

Example:

if True:
    if False:  # No indentation needed
        print('foo')
   print('bar')  # Incorrect indentation

IndentationError: expected an indented block

This error occurs when you create a compound statement (such as if, while, or for) without the corresponding block below it.

Example:

if True:
...
  # The body of the `if` statement is missing

IndentationError: unindent does not match any outer indentation level

This error occurs when you unindent a statement, but the indentation level does not match any previous statement in the same block.

Example:

if True:
    if True:
        print('foo')
   print('bar')  # Incorrect indentation (one space too few)

TabError: inconsistent use of tabs and spaces in indentation

This error occurs when you mix tabs and spaces in your code for indentation.

Example:

if True:
    if True:  # Tab used
        print('foo')
    print('bar')  # Space used

Recommended Indentation Style

• Use 4 spaces per indentation level
• Do not mix tabs and spaces

Tips for Correct Indentation

• Use a code editor that provides syntax highlighting and indent detection.
• When indenting, count the number of spaces or tabs needed out loud.
• Use consistent indentation throughout your code.
• Regularly run your code to catch indentation errors early on.

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