How to get the File Size in Python Program?

Aniruddha Chaudhari
Updated: Aug 05, 2020

To get the file size in Python, we can use the os module which comes inbuilt with the Python.

Module os has a sub-module path. This sub-module has the getsize() method associated with it. It can be used to get the size of the given file.

Syntax

os.path.getsize(<file_path>)

Arguments:
path (string): file path

Returns:
int : size of the file in bytes

Python Code

import os
file_path = "example.zip"

file_size = os.path.getsize(file_path)
print(f"Size of the file ({file_path}) is {file_size}")

If you are using only getsize() method in your Python program, it is better to import only this method instead of complete os module in your code.

from os.path import getsize
file_path = "example.zip"

file_size = getsize(file_path)
print(f"Size of the file ({file_path}) is {file_size}")

Output:

The output of the above both programs will be same.

Size of the file (example.zip) is 15787

Here, file example.zip has to be in the same directory from where you are running your Python script. Otherwise, you can also provide absolute path of the file.

By default, it returns the file size in bytes. You can convert it into the human-readable format like KB, MB, GB…

You can also take the file path as user input in Python.
For printing output, we have used f-string formatting.

If the file path is not valid, your program will throw an exception.

FileNotFoundError: [Errno 2] No such file or directory

If you are using the getsize() method to find the size of the file, it is good practice to handle this exception in Python.

To avoid this exception, you can also check whether the given file is present or not.

Use case

Many times, we need to check the file size in Python before processing it. For example, you can avoid certain operations (like file read-write operations) if the size of the file is zero (empty file).

If you are building project where user needs to upload any file, you can check the file size. If the file size is zero, you can prompt user to upload valid file. You can also check if the file is greater than some threshold value.

Aniruddha Chaudhari

I am a Python enthusiast who loves Linux and Vim. I hold a Master of Computer Science degree from NIT Trichy and have 10 years of experience in the IT industry, focusing on the Software Development Lifecycle from Requirements Gathering, Design, Development to Deployment. I have worked at IBM, Ericsson, and NetApp, and I share my knowledge on CSEstack.org.