Checks Python source code files for errors.

# To check a single Python file:
pyflakes check <path/to/file>.py

# To check Python files in a specific directory:
pyflakes checkPath <path/to/directory>

# To check Python files in a directory recursively:
pyflakes checkRecursive <path/to/directory>

# To check all Python files found in multiple directories:
pyflakes iterSourceCode <path/to/directory_1> <path/to/directory_2>