Python Indentations

A code block (body of function,loops,etc.) start with Indentations and end with the first unindented line .Generally four whitespace are used for indentation and is preferred over tabs.
Here is the example:

In the above example examine clearly after 'if' and 'else' statements , the next line here we started from taking some spaces , which is very must and this is only known as indentation in Python