How to Get File Size in Python

Filed Under: Python

We can get file size in Python using the os module.

File Size in Python

The python os module has stat() function where we can pass the file name as argument. This function returns a tuple structure that contains the file information. We can then get its st_size property to get the file size in bytes.

Here is a simple program to print the file size in bytes and megabytes.

# get file size in python
import os

file_name = "/Users/pankaj/abcdef.txt"

file_stats = os.stat(file_name)

print(f'File Size in Bytes is {file_stats.st_size}')
print(f'File Size in MegaBytes is {file_stats.st_size / (1024 * 1024)}')


File Size In Python

File Size In Python

If you look at the stat() function, we can pass two more arguments: dir_fd and follow_symlinks. However, they are not implemented for Mac OS.

Here is an updated program where I am trying to use the relative path but it’s throwing NotImplementedError.

# get file size in python
import os

file_name = "abcdef.txt"
relative_path ="/Users/pankaj", os.O_RDONLY)

file_stats = os.stat(file_name, dir_fd=relative_path)


Traceback (most recent call last):
  File "/Users/pankaj/.../", line 7, in 
    file_stats = os.stat(file_name, dir_fd=relative_path)
NotImplementedError: dir_fd unavailable on this platform
Python File Size Relative Path NotImplementedError

Python File Size Relative Path NotImplementedError


  1. John says:

    Thanks for the example. It was helpful. As an FYI I use a mac os version 10.15.5. The get info feature of Finder reports file size in multiples of 1,000,000 ( 1000 * 1000) not 1,048,596 (1024 * 1024). Not sure if this changed at some point.
    Thanks again

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