Indentation
Indentation is an empty space (whitespace) used at the beginning of any statement to start new paragraph.
indentation should be consistent throughout your code.
Indents
There are two types of indents:
Horizontal indents: spaces at the left 2 or 4 spaces.
Vertical indents(hanging indent): empty lines for splitting code into logical blocks.
Indentation in Python is mandatory.
Indentation in other languages like C,C++,Java etc is just for readability but in python, the indentation is a mandatory concept that should be followed when writing a python code, otherwise, python interpreter will thrown IndentationError.
Reason why indentation is important in python
because the indentation serves another purpose other than code readability
- To represent a block of code(Python treats the statements as a single block of code that have the same indentation level.)
- Without indentation, Python interpreter will get confused and does not know which statement to execute next or which statement belongs to which block.
- Indentation helps interpreter to understand the order in which each block/statement should be executed.
Python Indentation Rules
- The first line of Python code can’t have indentation, it will throw
IndentationError. - The best practice is to use 4 spaces for indentation.
- If you have multiple lines inside the if block, all the lines will need to be indented with same level otherwise You will get indentation error
- If there is colon at the end of a line, you will need to indent the next line/lines by ignoring your current level of indentation.
- If there is no colon, you should not indent the starting of a line.
- Python doesn't allow mixing tabs and spaces for indentation.
4-space or 2-space indentation
Indentation style
There are several styles .Pick a style that suits you, then use it consistently.
- Allman
- K&R(Kernighan & Ritchie Style)
- GNU
- Whitesmiths
- Horstmann
- Haskell
- Pico
- Ratliff
- Lisp
K&R(Kernighan & Ritchie Style) In K&R, single-line blocks do not have braces.