4.11 Code Blocks and indention

• A code block is a series of statements that are grouped together
  • The initial code block is not indented
  • A new code block can follow a statement that ends with a colon, such as an "if" or "else"
  • In addition, a new code block must be more indented than the previous code block.
  • Good practice is to use the standard recommended 4 columns per indentation level
• A common error for new Python programmers is the mixing of tabs and spaces.
  • Use 4 spaces
  • Many editors consider a tab to be equivalent to either 3 or 4 spaces, while in Python a tab is equivalent only to another tab.
  • A program that mixes tabs and space to indent code blocks will automatically generate an IndentationError from the interpreter in Python 3
  • Good practice is to use spaces only when indenting code, and to set text editor options to automatically use spaces when possible.

Example of indentation:

Special cases

• The number of columns of text considered to be acceptable varies from 80 to 120
• Good practice is to use the widely accepted standard of 80 columns.
  • A few exceptions to the rules of indentation deal with very long statements that require more than one line and wrap to the next line.
    • Does not count as a new code block