Decorators and Generators in Python

Python is an incredibly powerful and flexible programming language used in a wide variety of applications. Two key features that make it a favorite among developers are decorators and generators.

What are decorators?

Decorators are functions in Python that enable the programmer to modify the behavior of another function without modifying its source code. Decorators take in a function and return a modified version of that function. They can be used to provide additional functionality to an existing function, such as adding logging or timing to a function call.

Here’s a simple example of a decorator that adds timing to a function:

import time

def time_decorator(func):
    def wrapper(*args, \*\*kwargs):
        start_time = time.time()
        result = func(*args, \*\*kwargs)
        end_time = time.time()
        print(f"Execution time: {end_time - start_time}")
        return result
    return wrapper

def my_function():
    # Your function code here

The decorator time_decorator takes in a function as an argument and returns a new function wrapper that wraps the original function. When we apply the @time_decorator decorator to my_function, it replaces my_function with the wrapper function that includes timing information.

What are generators?

Generators are functions that can be used to create iterators. Iterators are objects that enable the programmer to iterate over a set of values one at a time. Generators are used to generate an arbitrary amount of data on the fly, rather than generating it all at once and storing it in memory.

Here’s an example of a generator that generates the Fibonacci sequence:

def fibonacci():
    a, b = 0, 1
    while True:
        yield a
        a, b = b, a + b

fib = fibonacci()

for i in range(10):

The fibonacci function is a generator that uses the yield keyword to generate the next value in the sequence. The fib variable is an instance of the generator object. We can use the next() function to get the next value in the sequence one at a time.


Decorators and generators are powerful features of Python that enable developers to write clean, powerful, and efficient code. Decorators can be used to add functionality to existing functions without modifying their source code, while generators can create iterators that generate data on the fly. By mastering these features, you can write more flexible and efficient code that is easier to read and maintain.

See also