PermissionError: [Errno 13] Permission denied

A PermissionError occurs when Python tries to access, modify, or delete a file or directory but lacks the required permissions. This error can happen due to:

1. Trying to open a file without read/write permission
2. Attempting to modify a protected system file
3. Opening a file in write mode without necessary access
4. Trying to execute a script without execution permission
5. Using a directory as a file (e.g., open("folder"))

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1. Common Causes and Fixes

Cause 1: Insufficient Permissions to Read/Write the File

If you don’t have permission to read or write to a file, Python will throw a PermissionError.

Incorrect Code:

with open("/root/protected.txt", "r") as file:
    content = file.read()

Problem: The file is in a restricted directory.

Solution: Run the script as an administrator/root or change permissions.

Fix: Change File Permissions

On Linux/macOS, use:

sudo chmod +r protected.txt  # Grant read access
sudo chmod +w protected.txt  # Grant write access

On Windows, right-click the file → Properties → Security → Edit Permissions.

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Cause 2: Trying to Write to a Read-Only File

If a file is read-only, writing to it will raise a PermissionError.

Fix: Modify File Permissions

chmod +w readonly.txt  # Linux/macOS: Add write permission

Or, change file attributes on Windows:

attrib -R readonly.txt

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Cause 3: Attempting to Open a Directory as a File

If you mistakenly try to open a directory instead of a file, Python will throw an error.

Incorrect Code:

with open("my_folder", "r") as file:
    content = file.read()

Problem: "my_folder" is a directory, not a file.

Solution: Ensure the path points to a valid file.

import os

path = "my_folder"
if os.path.isdir(path):
    print("This is a directory, not a file!")
else:
    with open(path, "r") as file:
        content = file.read()

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Cause 4: Trying to Write to a Restricted System File

Some files, like system logs or program files, require admin privileges to modify.

Fix: Run as Administrator

• On Linux/macOS, use sudo: bashCopyEditsudo python3 script.py
• On Windows, run Python as Administrator:
  Right-click Python → Run as Administrator.

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Cause 5: Trying to Delete a Read-Only File

If a file is marked as read-only, Python cannot delete it.

Fix: Remove Read-Only Attribute

• Linux/macOS: chmod +w myfile.txt # Add write permission rm myfile.txt # Now delete
• Windows: attrib -R myfile.txt del myfile.txt

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Cause 6: Locked File in Use by Another Program

If another process is using the file, Python cannot access it.

Fix: Close the file before running Python

1. Close it manually if open in an editor.
2. Check which program is using the file:
   • Windows: Use Resource Monitor
   • Linux/macOS: Use lsof bashCopyEditlsof myfile.txt
3. Restart your system to unlock the file.

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2. Handling PermissionError in Python

Use Try-Except to Handle the Error Gracefully

try:
    with open("protected.txt", "w") as file:
        file.write("Hello!")
except PermissionError:
    print("Permission denied! Try running as admin or changing file permissions.")

Use os.access() to Check Permissions Before Accessing

import os

file_path = "data.txt"

if os.access(file_path, os.W_OK):
    with open(file_path, "w") as file:
        file.write("Hello, world!")
else:
    print("You do not have write permission for this file.")

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3. Summary of Fixes

Issue	Fix
No read/write permission	Change file permissions (chmod / attrib -R)
Opening a directory as a file	Check with os.path.isdir()
Writing to a read-only file	Grant write access (chmod +w)
Deleting a protected file	Remove read-only flag (attrib -R)
File locked by another program	Close the file or restart system
Running script without admin rights	Run as administrator (sudo python3 script.py)