Python: Three ways to check if a file is empty

In this article, we will discuss different ways to check if a file is empty i.e. its size is 0 using os.stat() or os.path.getsize() or by reading its first character.

Check if a file is empty using os.stat() in Python

Python provides a function to get the statistics about the file,

os.stat(path, *, dir_fd=None, follow_symlinks=True)

It accepts file path (string) as an argument and returns an object of the structure stat, which contains various attributes about the file at the given path. One of these attributes is st_size, which tells about the size of the file in bytes.

Let’s use this to get the size of the file ‘mysample.txt’ and if size is 0 then it means, file is empty i.e.

import os

file_path = 'mysample.txt'

# check if size of file is 0
if os.stat(file_path).st_size == 0:
    print('File is empty')
else:
    print('File is not empty')

As our file is empty, so the output will be,

File is empty

P.S. We already had an empty file ‘mysample.txt’ in the same directory.

But we should be careful while using it because if the file doesn’t exist at the given path, then it can raise an Error i.e. FileNotFoundError,

FileNotFoundError: [WinError 2] The system cannot find the file specified: FILE_NAME

Therefore we should first check if the file exists or not before calling os.stat(). So, let’s create a separate function to check if file exists and it is empty i.e.

import os

def is_file_empty(file_path):
    """ Check if file is empty by confirming if its size is 0 bytes"""
    # Check if file exist and it is empty
    return os.path.exists(file_path) and os.stat(file_path).st_size == 0

This function first confirms if the file exists or not, if yes then it checks if its size is 0 or not (if file is empty).
Let’s use this function to check if file ‘mysample.txt’ is empty,

file_path = 'mysample.txt'
# check if file exist and it is empty
is_empty = is_file_empty(file_path)

if is_empty:
    print('File is empty')
else:
    print('File is not empty')

Output:

File is empty

It confirms that file ‘mysample.txt‘ is empty.

Check if file is empty using os.path.getsize() in Python

In Python os module provides another function i.e.

os.path.getsize(path)

It accepts the file path (a string) as an argument and returns the size of the file in bytes. If the file doesn’t exist and the given path then it raises os.error.

Let’s use this to get the size of file ‘mysample.txt‘ and if the size is 0 then it means, file is empty i.e.

import os

file_path = 'mysample.txt'

# check if size of file is 0
if os.path.getsize(file_path) == 0:
    print('File is empty')
else:
    print('File is not empty')

As our file is empty, so the output will be,

File is empty

If the file doesn’t exist at the given path, then it can raise an Error i.e. FileNotFoundError,

FileNotFoundError: [WinError 2] The system cannot find the file specified: FILE_NAME

Therefore, we should first check if the file exists or not. If file exist then only call os.path.getsize(). We have created a function which checks if file exists or not and if it exists then check if its empty or not,

import os

def is_file_empty_2(file_name):
    """ Check if file is empty by confirming if its size is 0 bytes"""
    # Check if file exist and it is empty
    return os.path.isfile(file_name) and os.path.getsize(file_name) == 0

Let’s use this function to check if file ‘mysample.txt’ is empty,

file_path = 'mysample.txt'

# check if file exist and it is empty
is_empty = is_file_empty_2(file_path)

if is_empty:
    print('File is empty')
else:
    print('File is not empty')

Output:

File is empty

It confirms that file ‘mysample.txt‘ is empty.

Check if the file is empty by reading its first character in Python

def is_file_empty_3(file_name):
    """ Check if file is empty by reading first character in it"""
    # open ile in read mode
    with open(file_name, 'r') as read_obj:
        # read first character
        one_char = read_obj.read(1)
        # if not fetched then file is empty
        if not one_char:
           return True
    return False

In this function, it opens the file at the given path in read-only mode, then tries to read the first character in the file.
If it is not able to read the first character then it means the file is empty else not.

Let’s use this function to check if file ‘mysample.txt’ is empty,

file_path = 'mysample.txt'

# check if file is empty
is_empty = is_file_empty_3(file_path)

print(is_empty)

Output:

File is empty

It confirms that file ‘mysample.txt’ is empty.

The complete example is as follows,

import os

def is_file_empty(file_path):
    """ Check if file is empty by confirming if its size is 0 bytes"""
    # Check if file exist and it is empty
    return os.path.exists(file_path) and os.stat(file_path).st_size == 0


def is_file_empty_2(file_name):
    """ Check if file is empty by confirming if its size is 0 bytes"""
    # Check if file exist and it is empty
    return os.path.isfile(file_name) and os.path.getsize(file_name) == 0


def is_file_empty_3(file_name):
    """ Check if file is empty by reading first character in it"""
    # open ile in read mode
    with open(file_name, 'r') as read_obj:
        # read first character
        one_char = read_obj.read(1)
        # if not fetched then file is empty
        if not one_char:
           return True
    return False


def main():

    print('*** Check if file is empty using os.stat() in Python ***')

    file_path = 'mysample.txt'

    # check if size of file is 0
    if os.stat(file_path).st_size == 0:
        print('File is empty')
    else:
        print('File is not empty')

    print('*** Check if file exist and its empty using os.stat() in Python ***')

    file_path = 'mysample.txt'
    # check if file exist and it is empty
    is_empty = is_file_empty(file_path)

    if is_empty:
        print('File is empty')
    else:
        print('File is not empty')

    print('*** Check if file is empty using os.path.getsize() in Python ***')

    file_path = 'mysample.txt'

    # check if size of file is 0
    if os.path.getsize(file_path) == 0:
        print('File is empty')
    else:
        print('File is not empty')

    print('Check if file exist and its empty using os.path.getsize() in Python')

    file_path = 'mysample.txt'

    # check if file exist and it is empty
    is_empty = is_file_empty_2(file_path)

    if is_empty:
        print('File is empty')
    else:
        print('File is not empty')

    print('Check if file is empty by opening and it and reading its first character in Python')

    file_path = 'mysample.txt'

    # check if file is empty
    is_empty = is_file_empty_3(file_path)

    print(is_empty)


if __name__ == '__main__':
   main()

Output:

Check if file is empty using os.stat() in Python
File is empty
Check if file exist and its empty using os.stat() in Python
File is empty
Check if file is empty using os.path.getsize() in Python
File is empty
Check if file exist and its empty using os.path.getsize() in Python
File is empty
Check if file is empty by opening and it and reading its first character in Python
True