Indentation in Python

Indentation is a very important concept of Python because without properly indenting the Python code, you will end up seeing IndentationError and the code will not get compiled.

Python Indentation

Python indentation refers to adding white space before a statement to a particular block of code. In another word, all the statements with the same space to the right, belong to the same code block.

Example of Python Indentation

• Statement (line 1), if condition (line 2), and statement (last line) belongs to the same block which means that after statement 1, if condition will be executed. and suppose the if condition becomes False then the Python will jump to the last statement for execution.
• The nested if-else belongs to block 2 which means that if nested if becomes False, then Python will execute the statements inside the else condition.
• Statements inside nested if-else belong to block 3 and only one statement will be executed depending on the if-else condition.

Python indentation is a way of telling a Python interpreter that the group of statements belongs to a particular block of code. A block is a combination of all these statements. Block can be regarded as the grouping of statements for a specific purpose. Most programming languages like C, C++, and Java use braces { } to define a block of code. Python uses indentation to highlight the blocks of code. Whitespace is used for indentation in Python. All statements with the same distance to the right belong to the same block of code. If a block has to be more deeply nested, it is simply indented further to the right. You can understand it better by looking at the following lines of code. 

Example 1

The lines print(‘Logging on to neveropen…’) and print(‘retype the URL.’) are two separate code blocks. The two blocks of code in our example if-statement are both indented four spaces. The final print(‘All set!’) is not indented, so it does not belong to the else block. 

Output:

Logging on to neveropen...
All set !

Example 2

To indicate a block of code in Python, you must indent each line of the block by the same whitespace. The two lines of code in the while loop are both indented four spaces. It is required for indicating what block of code a statement belongs to. For example, j=1 and while(j<=5): is not indented, and so it is not within the Python while block. So, Python code structures by indentation. 

Output:

1
2
3
4
5

Note: Python uses 4 spaces as indentation by default. However, the number of spaces is up to you, but a minimum of 1 space has to be used.