how to count the total number of lines in a text file using python

Question

For example if my text file is:

blue
green
yellow
black

Here there are four lines and now I want to get the result as four. How can I do th

Answer 1

this one also gives the no.of lines in a file.

a=open('filename.txt','r')
l=a.read()
count=l.splitlines()
print(len(count))