mozfile

Common errors

• [WinError 32] The process cannot access the file because it is being used by another process:

  cause Attempting to move or remove files/directories on Windows that are still locked by another process or application (e.g., explorer, antivirus). Standard `shutil` functions often fail in this scenario.
  fix Use `mozfile.move()` or `mozfile.remove()` instead of `shutil.move()` or `shutil.rmtree()`. `mozfile` includes retry logic for such errors, significantly improving reliability in these situations.

• [Errno 13] Permission denied:

  cause Similar to `WinError 32`, this often occurs when trying to modify or delete files/directories without sufficient permissions or when they are temporarily held by another process. This is common in automated testing environments.
  fix Switch to `mozfile.move()` or `mozfile.remove()`. These functions are designed to mitigate these common permission/access denial issues by retrying the operation with a delay.

Warnings

• gotcha Unlike `shutil.rmtree`, `mozfile.remove` will *not* raise an error if the target path does not exist. This can mask issues if your code expects `FileNotFoundError`.
  Fix: Explicitly check `os.path.exists()` before calling `mozfile.remove()` if you need to ensure the path existed, or adjust error handling to account for silent removal of non-existent paths.
• gotcha When replacing `shutil.move` or `shutil.rmtree` with `mozfile.move` or `mozfile.remove`, be aware of the altered error handling. While `mozfile` functions are more robust against temporary file locking, they may behave differently in edge cases or with specific error types.
  Fix: Thoroughly test existing code after migrating from `shutil` to `mozfile` to ensure compatibility with altered error handling and retry logic, especially for non-Windows environments where `shutil` might be sufficient.
• breaking The jump from version 2.x to 3.0.0 (released October 2022) for `mozfile`, after a long gap, may include undocumented breaking changes, even if the primary API for core functions like `move` and `remove` appears stable. Always review release notes or test thoroughly when upgrading across major versions.
  Fix: Consult `mozbase`'s official documentation and conduct comprehensive regression testing when upgrading to 3.0.0 from older major versions to identify any subtle behavior changes.

Install

• pip install mozfile Install stable version

Imports

• extract

  from mozfile import extract

• move
  wrong:

  import shutil; shutil.move(...)

  correct:

  from mozfile import move

  mozfile.move provides enhanced robustness, especially on Windows, by retrying operations on common file access errors.
• remove
  wrong:

  import shutil; shutil.rmtree(...)

  correct:

  from mozfile import remove

  mozfile.remove provides enhanced robustness, especially on Windows, by retrying operations and suppressing errors for non-existent paths (unlike shutil.rmtree).

Quickstart

This quickstart demonstrates the core utilities of `mozfile`: `move` and `remove`. These functions offer enhanced reliability over standard `shutil` operations, particularly in test environments and on Windows where file locking can be problematic. The `remove` function notably does not raise an error if the path does not exist.

import os
from mozfile import move, remove

# Create some dummy files/directories for demonstration
if not os.path.exists('test_dir_src'):
    os.makedirs('test_dir_src')
with open('test_dir_src/file1.txt', 'w') as f:
    f.write('hello world')

# 1. Use mozfile.move to move a file or directory
try:
    print(f"Moving 'test_dir_src/file1.txt' to 'file1_moved.txt'...")
    move('test_dir_src/file1.txt', 'file1_moved.txt')
    print(f"'file1_moved.txt' exists: {os.path.exists('file1_moved.txt')}")
finally:
    # Clean up after move
    if os.path.exists('file1_moved.txt'):
        os.remove('file1_moved.txt')

# 2. Use mozfile.remove to recursively delete a directory
# This version is more resilient to Windows file lock issues
print(f"Removing 'test_dir_src'...")
remove('test_dir_src')
print(f"'test_dir_src' exists: {os.path.exists('test_dir_src')}")

# 3. Demonstrate remove for non-existent path (no error)
print(f"Attempting to remove a non-existent path 'non_existent_dir'...")
remove('non_existent_dir')
print("No error raised, as expected for mozfile.remove on non-existent paths.")