text processing - How to delete all blank lines in the file with the help of python?

Question

For example, we have some file like that:

first line
second line

third line

And in result we have to get:

first line
second line
third line

Use ONLY python

Answer 1

import fileinput
for line in fileinput.FileInput("file",inplace=1):
    if line.rstrip():
        print line