Python Program to Get Line Count of a File

To understand this example, you should have the knowledge of the following Python programming topics:


Example 1: Using a for loop

The content of the file my_file.txt is

honda 1948
mercedes 1926
ford 1903

Source Code

def file_len(fname):
    with open(fname) as f:
        for i, l in enumerate(f):
            pass
    return i + 1

print(file_len("my_file.txt"))

Output

3

Using a for loop, the number of lines of a file can be counted.

  • Open the file in read-only mode.
  • Using a for loop, iterate through the object f.
  • In each iteration, a line is read; therefore, increase the value of loop variable after each iteration.

Example 2: Using list comprehension

num_of_lines = sum(1 for l in open('my_file.txt'))

print(num_of_lines)

Output

3
  • Open the file in read-only mode.
  • Using a for loop, iterate through open('my_file.txt').
  • After each iteration, return 1.
  • Find the sum of the returned values.

To learn more, visit Python List Comprehension.


Also Read:

Did you find this article helpful?

Your builder path starts here. Builders don't just know how to code, they create solutions that matter.

Escape tutorial hell and ship real projects.

Try Programiz PRO
  • Real-World Projects
  • On-Demand Learning
  • AI Mentor
  • Builder Community