Adventures in Machine Learning

Boosting Python Efficiency: Harnessing the Power of the Yield Keyword

Overview of Python Yield Keyword

The yield keyword in Python is used in the context of generators, a type of function that can be used to generate a sequence of numbers, characters, or other values. A generator function is defined like any other function, but instead of returning a value, it yields a sequence of values.

The yield keyword in the generator function pauses the execution of the function and returns the value to the caller. The next time the function is called, it resumes execution from where it left off and continues generating values until there are no more to generate.

Usage of Yield Keyword

The generator function in Python is an iterator, which has two main methods: __iter__() and __next__(). The __iter__() method returns an iterator object and the __next__() method returns the next value in the sequence.

Yield is used with the __next__() method to generate values one at a time. For example, let’s define a generator function that generates the first n Fibonacci numbers:

def fib(n):
a, b = 0, 1
for i in range(n):
yield a
a, b = b, a + b


When you call this function, it will return an iterator object that you can use to generate the first five Fibonacci numbers:

for i in


The output of this code would be:






Benefits of Using Yield Keyword

One of the key benefits of using yield is that it can help you deal with limited data efficiently. When working with large datasets, it may not be feasible to load the entire dataset into memory at once.

You can use yield to generate the data you need as you need it, without having to keep the entire data set in memory. This can help you avoid memory overflow errors and make your code run more efficiently.

Memory Efficiency

Yield can also be used to improve your codes memory efficiency. By only generating the data you need at each step, you can reduce the amount of memory your program uses, which can help speed up your program and prevent it from crashing.

Python Yield vs Return

The return statement is used to terminate a function, whereas yield returns a value and, in essence, pauses the function to allow resumption later. Return statements are used to return a value from a function and terminate its execution.

Yield works like a pause function inside a function and can be resumed later to generate more values. In some instances, the yield keyword can help you write much cleaner code.

As previously mentioned, by only returning the data you need, you reduce memory usage, making your code more efficient. In conclusion, both yield and return statements have unique features that make them useful in different situations.

However, the yield keyword provides more utility than return. It helps to write cleaner code, especially when dealing with limited data, and its ability to pause functions makes it a powerful option when working with large data sets.

It’s sure to make your Python code more efficient and maintainable. Python is a powerful and versatile programming language used by developers in various fields to simplify tasks such as data analytics, web development, and automation.

One of Python’s most significant advantages is its ability to handle large amounts of data and its extensive library of built-in modules. In this expansion, we will explore examples that illustrate how we can use the yield keyword and generator functions to improve efficiency and memory usage in Python.

Python Yield Example

Let’s take a look at an example of how you can use the yield keyword to generate random numbers. Here’s how you can return a given number of random numbers using the return statement:

import random
def generate_random_numbers(n):
result = []
for i in range(n):
result.append(random.randint(1, 100))
return result

In this example, the function generates a list of ten random numbers between 1 and 100 and returns it to the caller. Here’s how you can do the same thing using the yield function:

def generate_random_numbers_using_yield(n):
for i in range(n):
yield random.randint(1, 100)

In this example, the function generates a list of ten random numbers between 1 and 100, but instead of returning the entire list at once like in the previous example, it returns a generator object that you can use to generate the sequences on demand.

Python Generator Function Real World Example

One of the most common use cases for generators is reading large text files. Reading large text files can be resource-intensive due to the time needed to load the entire file into memory before it can be parsed.

However, using generators can help make processing of such files more efficient by breaking them into smaller chunks that can be read and parsed sequentially. Consider the following code:

def read_text_file(file_path):
with open(file_path, "r") as file_obj:
for line in file_obj:
yield line

In the above example, the generator function ‘read_text_file’ reads in the text file line by line, using the yield statement to pause execution after each line, returning it to the caller.

This allows you to process the file line by line, rather than loading it all into memory at once, which can be more efficient with large text files. Using generators and the yield keyword can significantly improve the performance and memory usage of a program.

It can help you to save memory by only loading the data you need, thus keeping your system from crashing due to low memory. Additionally, generator functions, when used properly, can greatly reduce processing time for large datasets, allowing for more efficient execution of projects.


In this article expansion, we have explored how the yield keyword and generator functions can improve the efficiency of your Python code. Yield can help you work with limited data efficiently and reduce memory usage, thus speeding up your program and preventing it from crashing.

In contrast, the yield keyword allows a function to pause and resume later, making it a powerful option when working with large data sets. Furthermore, we have learned how generator functions can be used in real-world examples such as processing large text files.

These examples serve as a testament to the usefulness of generator functions in improving the memory efficiency and processing speed of your Python code. Python is a versatile programming language used extensively in various fields such as data science, machine learning, automation, and more.

One of the key features of Python is the generator function, which can help improve the performance and efficiency of code when working with large data sets. In this expansion, we will explore two additional features that can help expand the capabilities of the yield keyword in Python.

Python Yield Send Example

The send method is a function provided by the generator object that allows you to send values to a generator function while it is running. This can be particularly useful in cases where you want to pass data to the generator without having to modify the generator function’s parameters.

Here’s an example of how you can use the send method in your generator function.

def my_generator_function():
while True:
received_value = yield
print(f"Received Value: {received_value}")
my_generator = my_generator_function()
next(my_generator) # run the generator to the first yield statement

In this example, the my_generator_function() creates an infinite loop that waits to receive input via the yield keyword.

The next() method is used to advance the generator function to the first yield statement so that the generator can be ready to receive input via the send() method. The send() method sends “Hello” and “World” to the generator function, which then prints the received values.

Python Yield From Example

The yield from statement is another feature that can be used with generator functions to simplify your code. It allows you to create a sub-iterator within a generator that can generate values on its own.

By doing this, you can nest generators and simplify the code you need to write to manage complex data sets without having to create custom iterations or sub-iteration methods. Here is an example of how the yield from statement can be used to simplify a generator function.

def digits(n):
for i in range(n):
yield i
def square(numbers):
for number in numbers:
yield number ** 2
my_generator = square(digits(3))

In this example, the digits() function generates a sequence of numbers from 0 to n, and the square() function applies the square operation to each number in the list. We combine the generators using a nested generator expression.

Now let’s see how we can simplify this code using the yield from statement:

def square_with_yield_from(numbers):
yield from (number ** 2 for number in numbers)
my_generator = square_with_yield_from(digits(3))

With the yield from statement, you can simplify the square function by using a simpler generator expression. The yield from statement automatically creates a sub-iterator that generates the values from the provided sequence, and the values are passed to the parent generator.


In this article expansion, we have explored two additional features of Python’s yield keyword that can help make your code more efficient and easier to manage. The send method allows you to send data to a running generator function, simplifying your code when multiple values need to be processed.

The yield from statement allows you to create sub-iterators for your generator function, simplifying code for complex data sets. By using these tools, you can create more efficient, elegant, and maintainable code in your Python projects.

In conclusion, the yield keyword in Python is a powerful asset that can help improve the performance and efficiency of your code, especially when dealing with large datasets. In this article, we explored various features of the yield keyword, including the send method, the yield from statement, and the benefits of using yield over the return statement.

By using these tools, Python developers can create more efficient, elegant, and maintainable code that is better suited to real-world scenarios. Regardless of the industry or project scope, the yield keyword is an essential tool that can help elevate your Python code to the next level.

Popular Posts