Final answer:
To test smaller pieces of Python code, unit testing with frameworks like unittest, using doctest within the docstrings, and interactive environments (IDEs) can be used. Immediate feedback can also be obtained by using the Python REPL for interactive testing and debugging.
Step-by-step explanation:
To test smaller pieces of Python code, one commonly used method is unit testing. Unit testing involves writing tests for the smallest parts of your code, which typically means functions and methods. A popular framework for this in Python is unittest, which is included in the Python standard library. This framework allows you to write test cases that can be run to verify that your code is behaving as expected.
Another option is to use doctest, which allows you to write tests within the docstrings of your Python functions. These tests can be executed to check if the code is performing correctly. For more immediate feedback, many developers rely on interactive development environments (IDEs) like PyCharm or Visual Studio Code which offer debugging tools and live code evaluation.
For more isolated and interactive testing, Python's interactive interpreter, known as the REPL (Read-Eval-Print Loop), can be used. It allows you to run small pieces of code directly and see the results immediately, which is especially useful for experimenting with new ideas or debugging.