Is indentation compulsory after if statements? What we have to do if the program contains multiple lines?

Question

If program contains multiple lines it will be very difficult for us to indent for each line know. Is there any other process?

Answer 1

No, indentation is not difficult if you are using IDE or special code / text editors
otherwise code will not work properly, and most likely will occur an error

Answer 2

Python: yes you have to
Many other languages: no

Many editors allow for code formatting to automate the process of indentation for you tho