Section 1.1: Skillful Importing of Python Modules

When developing software, it’s almost unavoidable to use existing modules. Thus, mastering the art of importing modules correctly is crucial. The basic syntax for importing in Python is as follows:

from A import B

While the from A part is optional, it's essential not to underestimate the nuances of importing. Here are three tips to enhance your importing practices and minimize errors:

1. Avoid Using Asterisks for Bulk Imports

You might be tempted to use the asterisk to import everything at once:

from module_a import *

Although this seems convenient, it’s ill-advised. Importing everything can lead to confusion regarding what has been imported, which may introduce bugs. For instance, conflicts can arise if the names in your current file clash with those from the imported module. Furthermore, if new items are added to the imported module, they will automatically be included, increasing the risk of name clashes. A best practice is to import only what is necessary.

2. Use Aliases for Simplicity

For data scientists, the following lines of code are likely familiar:

import numpy as np

import pandas as pd

import matplotlib.pyplot as plt

By employing the as keyword, you can assign shorter, more convenient aliases to lengthy module names. This small adjustment significantly enhances your coding efficiency.

3. Implement Relative Imports Intelligently

Relative imports allow you to succinctly import modules relative to the current file's location:

from . import module_a

from .. import module_b

Here, a single dot indicates that module_a is sourced from the same directory as the current file (siblings), while two dots denote that module_b is imported from the parent directory. This practice can streamline your code.

The first video, "10 Useful Python Modules You NEED to Know," offers insights into essential modules that can enhance your Python programming experience.

Section 1.2: Running Python Modules as Scripts

In addition to importing modules, you can execute them independently as scripts. Consider a simple module named test.py containing the line:

print("Yang Zhou")

To run this module directly in a terminal, you would simply input:

python test.py

The result will display the output directly in the terminal.

For modules that contain functions or classes, you can still execute them as scripts by defining a main function. Here’s how you might modify test.py:

def main():

print("Executing the main function")

if __name__ == "__main__":

main()

When you execute this module in the terminal, the code within the if __name__ == "__main__" block will run. This conditional check allows for flexibility; if the module is imported elsewhere, the code within that block will not execute, preventing unintended behavior.

The second video, "Python 3 Tutorial for Beginners #19 - Modules & Packages," covers the foundational concepts of modules and packages, helping beginners understand their structure and usage.

Related Article:

5 Uses of Asterisks in Python

Exploring the powerful capabilities of asterisks for writing more elegant code.