How to Check If a File Exists in Python (in 2 Ways)

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Checking if file exists in Python
Check if a file exists using Python. Image design by Elias Ervast

To check if a file exists using Python, use the exists() function from the os.path module:

from os.path import exists

if exists(path_to_file):
    # Do something

Here is a short illustration of checking if a file exists in the same folder:

Python how to check if file exists

Alternatively, you can use the is_file() function from the Path class from the pathlib module:

from pathlib import Path

path = Path(path_to_file)

if path.is_file():
    # Do something

Where path_to_file is relative to the Python file that checks the existence of the file.

For example, if there’s a file called hello.txt in the same folder as this Python program, the path_to_file is the name of the file.

Check If a File Exists—A Step-by-Step Guide

Before you start working with a file, you may want to check if one exists. To do this you can use the exists() function from os.path module.

Step 1. Include the os.path Module

The os.path module is is useful when processing files from different places in the file system of your program.

Make sure you import the os.path module before trying to use it:

import os.path

Step 2. Call os.path.exists() Function

After including the os.path module, call the exists() function. Remember to pass it the name or path of the file as an argument:

os.path.exists(path_to_file)

Where path_to_file is the path to the file you are seeking (relative to the Python file’s path). If the file is in the same folder as your Python program, the path is just the name of the file.

If the file exists, the exists() function returns True. Otherwise, it returns False.

The following example program uses the exists() function to check if the hello.txt file exists:

import os.path

file_found = os.path.exists('hello.txt')

print(file_found)

If the hello.txt file exists, you’ll see the following output:

True

Step 3. (Optional) Make the Call Shorter

To make the call to the exists() function shorter, import the function from the module:

from os.path import exists

exists('hello.txt')

And here is an example where the file is in another folder called some_files:

Python how to check if file exists

Here you need to provide the path to the file to find out if it exists. Because the folder where the file is, is in the same folder as the Python program, its path is:

some_files/hello.txt

Now, this is how you can use the os module to check if a file exists in Python. But there’s an alternative approach by using the relatively new pathlib module.

Check If a File Exists Using ‘Pathlib’

The pathlib module lets you manipulate files and folders.

To use it, import the Path class from the pathlib module:

from pathlib import Path

Then, create a Path object by initializing it with the file path whose existence is the point of interest:

path = Path(path_to_file)

Now, check if the file exists using the is_file() method. This essentially tests if the object you created is a valid file.

path.is_file()

For instance, let’s use this approach to see if the hello.txt file exists:

from pathlib import Path

path_to_file = 'hello.txt'
path = Path(path_to_file)

if path.is_file():
    print(f'{path_to_file} exists')
else:
    print(f'{path_to_file} does not exist')

If the hello.txt file exists, you’ll see the following output:

hello.txt exists

Conclusion

Today you learned how to check if a file exists in Python.

To take home, you can use the exists() method from the os.path library. To use this method, all you need to do is import the exists() method from os.path module and call the method by passing a file path as an argument.

Thanks for reading!

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