When writing Python code, it is common practice to include docstrings for functions. Docstrings are used to provide documentation and information about the purpose, usage, and parameters of a function. However, the question arises whether docstrings are necessary for internal functions in Python.

Option 1: No Docstrings for Internal Functions

One approach is to argue that docstrings are not necessary for internal functions. Internal functions are typically used within a module or class and are not intended to be accessed directly by external users. Since internal functions are not part of the public interface, it may be argued that documenting them with docstrings is unnecessary.

def internal_function():
    # Code for internal function
    pass

def public_function():
    """This is a public function."""
    internal_function()

In this example, the internal_function() does not have a docstring, while the public_function() does. This approach can be justified by the fact that internal functions are typically shorter and more focused, making their purpose and usage self-explanatory within the context of the module or class.

Option 2: Minimal Docstrings for Internal Functions

Another approach is to include minimal docstrings for internal functions. Instead of providing detailed documentation, a brief description of the function’s purpose can be included. This can help future developers understand the intention behind the function and its role within the codebase.

def internal_function():
    """Internal function for performing a specific task."""
    # Code for internal function
    pass

def public_function():
    """This is a public function."""
    internal_function()

In this example, the docstring for internal_function() provides a concise description of its purpose. This approach strikes a balance between providing some documentation for internal functions without going into excessive detail.

Option 3: Detailed Docstrings for Internal Functions

The third option is to treat internal functions the same way as public functions and provide detailed docstrings for them. This approach ensures consistency in documentation across the codebase and can be beneficial for future maintenance and understanding of the code.

def internal_function():
    """
    Internal function for performing a specific task.
    
    Parameters:
    - None
    
    Returns:
    - None
    """
    # Code for internal function
    pass

def public_function():
    """This is a public function."""
    internal_function()

In this example, the docstring for internal_function() includes information about its parameters and return value, even though they are not relevant in this specific case. This level of documentation can be helpful for future developers who may need to modify or understand the internal function.

After considering these three options, it is recommended to choose Option 2: Minimal Docstrings for Internal Functions. This option strikes a balance between providing some documentation for internal functions without overwhelming the codebase with excessive documentation. It ensures that the purpose of internal functions is clear without going into unnecessary detail.