Python Program to Get Line Count of a File

In this example, you will learn to get line count of a file.

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

• Python enumerate()
• Python File I/O
• Python for Loop

1. 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.

2. 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.