Best Practices for Writing Clean and Efficient Python Code

Huzaifa Zahoor
3 min readMar 20, 2023

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Python is a versatile language that is widely used in a variety of domains, from web development to data science. Writing clean and efficient code is crucial to ensuring that your Python programs are easy to understand, maintain, and scale. This article will discuss some of the best practices for writing better code in Python.

Use Descriptive Variable Names

When writing code, use descriptive variable names that convey the purpose of the variable. Avoid single-letter variable names, as they are not informative and can be easily confused with other variables. Also, use underscores to separate words in variable names, such as first_name instead of firstname.

Follow PEP 8 Guidelines

PEP 8 is a set of guidelines for writing Python code that is readable, consistent, and easy to maintain. Following PEP 8 guidelines can help you avoid common coding mistakes and improve the readability of your code.

Some of the key guidelines include:

  • Indent your code using 4 spaces (not tabs).
  • Limit line length to 79 characters.
  • Use lowercase letters for variable names.
  • Use uppercase letters for constant names.
  • Use spaces around operators and after commas.

Use Function and Class Docstrings

Documentation is an essential aspect of writing good code. Python provides built-in support for docstrings, which are strings that provide documentation for functions, classes, and modules. Docstrings should describe the purpose of the function, the input parameters, the return value, and any exceptions that may be raised.

def calculate_area(radius):
"""
Calculate the area of a circle given its radius.

Args:
radius (float): The radius of the circle.

Returns:
float: The area of the circle.
"""
pi = 3.14159
area = pi * radius ** 2
return area

Write Modular Code

Modular code is code that is organized into smaller, reusable components. Writing modular code can make it easier to understand, maintain, and test your code.

  • Some strategies for writing modular code include:
  • Breaking your code into functions or classes that perform a single, well-defined task.
  • Avoiding hard-coding values in your code.
  • Using constants or configuration files to store values that may change.
def add_numbers(a, b):
return a + b

def multiply_numbers(a, b):
return a * b

sum = add_numbers(2, 3)
product = multiply_numbers(4, 5)

print(sum)
print(product)

Use Exception Handling

Exception handling is a way to handle errors in your code gracefully. Instead of crashing your program, exception handling allows you to catch and handle errors in a way that makes sense for your program.

Some best practices for exception handling include:

  • Only catch exceptions that you can handle.
  • Providing informative error messages.
  • Using the finally block to ensure that resources are released even if an exception occurs.
try:
x = int(input("Enter a number: "))
y = 10 / x
print("Result:", y)
except ValueError:
print("Invalid input. Please enter a number.")
except ZeroDivisionError:
print("Cannot divide by zero.")
finally:
print("Execution complete.")

Avoid Using Global Variables

Global variables are variables that are defined outside of a function or class and can be accessed from anywhere in the program. While they may seem convenient, global variables can make your code harder to understand and debug. Instead of using global variables, consider passing variables as arguments to functions or using class attributes.

Optimize Your Code

Python is an interpreted language, which means that it may not always be as fast as compiled languages like C or C++. However, there are several ways to optimize your Python code, such as:

  • Using list comprehensions instead of loops.
  • Using built-in functions instead of custom functions.
  • Avoiding unnecessary function calls.
  • Using generators instead of lists.

Conclusion

Writing clean and efficient code in Python is essential to creating programs that are easy to understand, maintain, and scale. By following these best practices, you can improve the readability and performance of your Python code. Remember to use descriptive variable names, follow PEP 8 guidelines, write modular code, use exception handling, avoid using global variables, and optimize your code.

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Huzaifa Zahoor

Huzaifa Zahoor is a Python developer and data engineer with over 3 years of experience in building web applications for the stock market.