How to Fix: PermissionError: [Errno 13] Permission denied

This error means Python tried to access a file or folder, resulting in a PermissionError: Permission denied, but the Operating System said “NO!”

Cause 1: The File is Open Elsewhere (Most Common on Windows)

If you have data.csv open in Excel, and you try to run a Python script that writes to that same data.csv, it will fail. Excel “locks” the file so nothing else can change it while you’re working.

The Fix: Close the file in all other programs (Excel, Word, etc.) and run your script again.

Cause 2: Trying to Write to a Folder, Not a File

Sometimes you mix up your paths.

# 'my_folder' is a directory, not a file!
with open("C:/Users/Name/Documents/my_folder", "w") as f:
    f.write("Hello")
# CRASH! PermissionError

The Fix: Make sure your path includes the actual filename at the end: .../my_folder/data.txt.

Cause 3: Actual Permissions (Admin Rights)

You might be trying to write to a protected system folder (like C:\Program Files on Windows or /etc/ on Linux) without administrator privileges.

The Fix: Either run your terminal/IDE as Administrator (not recommended for security reasons) or, better yet, save your files to a folder you own, like Documents or Desktop.