Now that you have seen just how useful modular programming techniques are, you might wonder why anyone would not want to use them. Other than a lack of understanding, why would a programmer eschew modular principles and techniques?
The Python language has been designed from the ground up to support good modular programming techniques, and with the addition of excellent tools such as the Python Standard Library, unit tests, and docstrings, it encourages you to apply these techniques to your everyday programming practice. Similarly, the use of indentation to define the structure of your code automatically encourages you to write well-formatted source code where the indentation of your code reflects the logical organization of your program. These are not random choices: Python encourages good programming practices every step of the way.
Of course, just like you can write poorly structured and incomprehensible spaghetti code using Python, it is possible to avoid using...