Comparing range() and xrange() in Python: What’s the Difference?

Sakshi Raheja Last Updated : 13 Jan, 2024
3 min read

Introduction

In the world of Python, there are many ways to achieve the same result. However, the efficiency and performance of these methods can vary significantly. Today, we’re going to study a hotly debated topic among Python enthusiasts – the battle between range() and xrange()in python. We’ll explore their differences, their uses, and ultimately, which one comes out on top.

Python has rapidly become the go-to language in data science and is among the first things recruiters search for in a data scientist’s skill set. Are you looking to learn Python to switch to a data science career?

Understanding range() and xrange()

Before we dive into the comparison, let’s first understand what range() and xrange() are. Both are built-in functions in Python that generate a sequence of numbers. The range() function, available in both Python 2.x and 3.x, returns a list of numbers, while xrange(), only available in Python 2.x, returns an object that generates numbers on the fly, making it more memory efficient.

Using range:

# Example usage of range()

for i in range(10):

    print(i)

# In Python 2.x, you could do:

for i in xrange(10):

    print(i)

Return Type

Example:

# range() creates a list with 1000000 elements

numbers_range = range(1000000)  # Could consume a lot of memory

# xrange() creates a generator that yields values as needed

numbers_xrange = xrange(1000000)  # More memory-efficient

 

# testing the type

print("The return type of range() is : ")

print(type(numbers_range))

 

# testing the type

print("The return type of xrange() is : ")

print(type(numbers_xrange))

Output:

The return type of range() is : 

<type 'list'>

The return type of xrange() is : 

<type 'xrange'>

The Memory Game

One of the key differences between range() and xrange() lies in their memory usage. Since range() generates a list, it consumes more memory, especially when dealing with a large sequence of numbers. On the other hand, xrange() generates numbers on demand, making it a more memory-friendly option. However, it’s worth noting that in Python 3.x, the range() function behaves like xrange(), offering the best of both worlds.

Example:

import sys

# range() creates a list with 1000000 elements

numbers_range = range(1000000)  # Could consume a lot of memory

# xrange() creates a generator that yields values as needed

numbers_xrange = xrange(1000000)  # More memory-efficient

 

# testing the size

# range() takes more memory

print ("The size allotted using range() is : ")

print (sys.getsizeof(numbers_range))

 

# testing the size

# xrange() takes less memory

print ("The size allotted using xrange() is : ")

print (sys.getsizeof(numbers_xrange))

Output:

The size allotted using range() is : 

8000072

The size allotted using xrange() is : 

40

Speed and Performance

When it comes to speed, the results can be surprising. While one might assume that xrange(), with its on-demand generation, would be faster, this isn’t always the case. For smaller ranges, range() can often be quicker due to its pre-generated list. However, for larger ranges, xrange() tends to have the upper hand due to its lower memory usage.

Compatibility and Usage

As mentioned earlier, xrange() is only available in Python 2.x. So, if you’re working with Python 3.x, range() is your only option. However, the revamped range() in Python 3.x offers similar functionality to xrange(), making it a versatile choice for all your number generating needs.

Difference between range() & xrange()

Featurerange() (Python 2)xrange() (Python 2)range() (Python 3)
Type returnedListGeneratorGenerator-like object
Memory usageCreates a full listGenerates on demandGenerates on demand
PerformanceFaster for small ranges or frequent single accessFaster for large ranges and memory-intensive tasksFaster for large ranges and memory-intensive tasks
FunctionalitySupports list operations (indexing, slicing, etc.)Only supports iterationOnly supports iteration
Python versionAvailableAvailableReplaced xrange()

Conclusion

So, who’s the winner in the battle between range() and xrange()? Well, it depends. If you’re working with Python 2.x and dealing with large ranges, xrange() might be your best bet. However, for Python 3.x users or those dealing with smaller ranges, range() is a reliable and efficient choice. Ultimately, understanding the differences and strengths of each function will allow you to make the best choice for your specific needs.

Python has rapidly become the go-to language in data science and is among the first things recruiters search for in a data scientist’s skill set. Are you looking to learn Python to switch to a data science career?

I am a passionate writer and avid reader who finds joy in weaving stories through the lens of data analytics and visualization. With a knack for blending creativity with numbers, I transform complex datasets into compelling narratives. Whether it's writing insightful blogs or crafting visual stories from data, I navigate both worlds with ease and enthusiasm. 

A lover of both chai and coffee, I believe the right brew sparks creativity and sharpens focus—fueling my journey in the ever-evolving field of analytics. For me, every dataset holds a story, and I am always on a quest to uncover it.

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