Consider the situation where you want to make a list of lines of a file; in that case, the readlines() method allows you to do that.

See the code in readlines1.py:

file_input = open("sample1.txt",'r')
print  file_input.readlines()
file_input.close()

Let's check the output of the code:

In the preceding screenshot, you can easily see the list of lines.

For reading purposes, you can loop over the file object. Let's analyze the code in readfileforloop.py:

file_input = open("sample1.txt",'r')
for line in file_input:
      print line

This is the output:

You can see all the lines. This is memory efficient, fast, and leads to simple code.