PYTHON — View Function Signatures in Python

Digital design is like painting, except the paint never dries. — Neville Brody

Viewing Function Signatures in Python

When working in Python, it’s important to be able to view function signatures, docstrings, and source code. This can help you understand what a function or method does without having to look up its documentation. In this tutorial, we’ll explore how to view function signatures and other related information using bpython, an enhanced REPL for Python.

Function Signatures and Default Values

In bpython, when you type an opening parenthesis to call a function or method, it will display the corresponding function signature with its formal parameters and their default values. It also shows information on which ones are positional, positional-only, keyword, or keyword-only arguments.

>>> def example_function(arg1, arg2=10, *args, kwarg1, kwarg2=20, **kwargs):
...     pass
...
>>> example_function(

Providing Function Arguments

As you provide values for your function, bpython highlights the current parameter name in the function signature to indicate how many arguments are left. This can be really helpful when the function expects multiple arguments.

>>> example_function(5, kwarg1=15,

Viewing Docstrings

In addition to function signatures, bpython displays docstrings from the function’s body if it can find and extract one from the source code. A docstring is usually a multiline string literal that immediately follows the function signature and contains a human-readable description of the function.

>>> def example_function(arg):
...     """
...     This is a docstring that describes the function.
...     """
...     pass
...

Viewing Source Code

If you need more information beyond the function signature and docstring, you can use bpython to reveal the underlying source code. In bpython, you can display a read-only preview of the corresponding source code by pressing F2. This allows you to navigate to the definition of a symbol by clicking on it or holding a designated key.

Conclusion

Understanding function signatures, docstrings, and source code can greatly enhance your Python programming experience. By using bpython, you can efficiently access this information within your Python REPL, making it easier to write and debug code.

In the next section of the course, you’ll learn how bpython can help you when mistakes are made during programming.

Happy coding!