invert_lines_step.py

# This is a comment in Python

import sys #imports system files

for line in sys.stdin:
        line = line.strip() # Strips a string of its trailing white spaces # Tabs tell python that it is part of the loop
        word = line.split(' ') # Makes a list of substrings by using space as as delimiter 
        s = ' '.join(word[::-1]) # [::-1] reverses the contents of a list # The syntax for join is counter intuitive, first you write the delimiter and then the list.
        print s # Prints the string