Python Enumerate Function

Introduction

Before we begin talking about the basics of Python Enumerate Function, let's briefly understand – What is Python Enumerate Function?

The Python enumerate() function is a handy built-in function that allows you to loop over an iterable object while keeping track of the index or position of each item. It adds a counter to an iterable, returning an enumerate object that contains tuples of both the index and the corresponding item.

This function simplifies the code by providing an elegant way to iterate over sequences and access their elements along with their positions. With Python enumerate(), you can easily enhance your programs' readability and maintainability.

Advantages of Python Enumerate Function

1. Simplifies Iteration: Python enumerate() simplifies the process of iterating over a sequence while keeping track of the index or position of each item.
2. Easy Access to Index: It provides a convenient way to access the index or position of each element in the iterable.
3. Enhanced Readability: The use of enumerate() improves code readability by making it clear that both the index and element are needed.
4. Code Conciseness: With enumerate(), you can achieve the same result with fewer lines of code compared to traditional iteration methods.
5. Efficient and Elegant: The enumerate() function offers an efficient and elegant solution for iterating and managing the index of elements in Python programs.

Python enumerate() Function

The syntax for the enumerate() function is as follows:

enumerate(iterable, start=0)

The function takes two arguments:

• iterable - An object that facilitates iteration.
• start - This is an optional argument that denotes the number from which the counter starts. The counter is set to start from 0 by default.

You may call the __next__() (or next() in Python 2) function on the enumerate object that enumerate() returns to get a tuple containing a count and the current value of the iterable.

enumerate() provides an enumerate object, on which you may call the next() (or next() in Python 2) function to retrieve a tuple containing a count and the current value of the iterable.

Using list() to create a list of tuples and looping over an iterable are demonstrated in the following example:

directions = ["north", "east", "south", "west"] 
list(enumerate(directions))

for index, value in enumerate(directions): 
    print("{}: {}".format(index, value))

Output

[(0, 'north'), (1, 'east'), (2, 'south'), (3, 'west')]

0: north
1: east
2: south
3: west

Choose a different starting index for the enumeration if the zero-based indexing is not effective for you:

directions = ["north", "east", "south", "west"] 
list(enumerate(directions, 1))

Output

[(1, 'north'), (2, 'east'), (3, 'south'), (4, 'west')]

The enumerate() function can be applied to any iterable object. A container that can be iterated over is called an iterable. To put it simply, it refers to an object that can be looped over with a for loop. The majority of Python's built-in objects, such as strings, lists, and tuples, are iterables.

Write More Pythonic Code with enumerate()

Unlike the conventional C-style for loop that is found in many programming languages, the for loop in Python is completely different. Python's for loop is equivalent to the foreach loop in other programming languages.

When working with iterables, beginner Python programmers frequently use the range(len(...)) pattern or set and increment a counter to obtain the corresponding index:

planets = ["Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"]
for i in range(len(planets)):
    print("Planet {}: {}".format(i, planets[i]))

planets = ["Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"]
i = 0
for planet in planets:
    print("Planet {}: {}".format(i, planet))
    i += 1

Using enumerate(), the loops shown before can be rewritten in a more conventional way:

planets = ["Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"]
for index, value in enumerate(planets): 
    print("Planet {}: {}".format(index, value))

Each approach will produce the same result:

Output

Planet 0: Mercury
Planet 1: Venus
Planet 2: Earth
Planet 3: Mars
Planet 4: Jupiter
Planet 5: Saturn
Planet 6: Uranus
Planet 7: Neptune

FAQs About Python Enumerate Function

Conclusion

In this tutorial, you have learned how to use Python’s enumerate() function.

If you have any queries, please leave a comment below, and we’ll be happy to respond to them.