What's ending comma in print function for?

Question

This code is from http://docs.python.org/2/tutorial/errors.html#predefined-clean-up-actions

with open(\"myfile.txt\") as f:
    for line in f:
        print          


        

Answer 1

in python 2.7:

print line,

in python 3.x:

print(line, end = ' ')