Python enumerate() Function

The enumerate() function is used when you need to loop through an iterable while getting both the index and the value at the same time.

It is commonly used with:

• Lists
• Tuples
• Strings
• Dictionaries
• Other iterable objects

Basic Syntax

enumerate(iterable, start=0)

The default starting index is 0.

Example:

names = ["Ram", "Sita", "Hari"]

for index, name in enumerate(names):
    print(index, name)

Output:

0 Ram
1 Sita
2 Hari

1. Why Use enumerate()?

Without enumerate(), you might write:

names = ["Ram", "Sita", "Hari"]

for i in range(len(names)):
    print(i, names[i])

Output:

0 Ram
1 Sita
2 Hari

With enumerate():

names = ["Ram", "Sita", "Hari"]

for i, name in enumerate(names):
    print(i, name)

It is shorter and easier to read.

2. Basic Example

fruits = ["Apple", "Banana", "Mango"]

for index, fruit in enumerate(fruits):
    print(index, fruit)

Output:

0 Apple
1 Banana
2 Mango

Here:

index

contains the position, while:

fruit

contains the actual value.

3. Start Index from 1

By default, indexing starts from 0.

You can change this using the start parameter.

names = ["Ram", "Sita", "Hari"]

for index, name in enumerate(names, start=1):
    print(index, name)

Output:

1 Ram
2 Sita
3 Hari

This is very useful when creating numbered lists.

4. Start Index from 100

The starting value doesn't have to be 1.

names = ["Ram", "Sita", "Hari"]

for index, name in enumerate(names, start=100):
    print(index, name)

Output:

100 Ram
101 Sita
102 Hari

The index increases by 1 for each item.

5. enumerate() with Strings

Strings are iterable.

word = "Python"

for index, character in enumerate(word):
    print(index, character)

Output:

0 P
1 y
2 t
3 h
4 o
5 n

6. Start String Index from 1

word = "Python"

for position, character in enumerate(word, start=1):
    print(position, character)

Output:

1 P
2 y
3 t
4 h
5 o
6 n

7. enumerate() with Tuples

languages = ("Python", "JavaScript", "PHP", "Java")

for index, language in enumerate(languages):
    print(index, language)

Output:

0 Python
1 JavaScript
2 PHP
3 Java

8. enumerate() with a Dictionary

When directly iterating over a dictionary, enumerate() gives the index and dictionary key.

students = {
    "Ram": 75,
    "Sita": 85,
    "Hari": 65
}

for index, name in enumerate(students):
    print(index, name)

Output:

0 Ram
1 Sita
2 Hari

If you need both the student name and marks:

students = {
    "Ram": 75,
    "Sita": 85,
    "Hari": 65
}

for index, (name, marks) in enumerate(students.items()):
    print(index, name, marks)

Output:

0 Ram 75
1 Sita 85
2 Hari 65

9. enumerate() with start=1

This is common when displaying data to users.

students = ["Ram", "Sita", "Hari", "Gita"]

for number, student in enumerate(students, start=1):
    print(number, student)

Output:

1 Ram
2 Sita
3 Hari
4 Gita

You can use this to create a numbered menu:

courses = [
    "Python",
    "Django",
    "MERN",
    "Data Science"
]

for number, course in enumerate(courses, start=1):
    print(f"{number}. {course}")

Output:

1. Python
2. Django
3. MERN
4. Data Science

10. Get a Specific Index

You can use enumerate() to find the position of a particular value.

names = ["Ram", "Sita", "Hari", "Gita"]

for index, name in enumerate(names):
    if name == "Hari":
        print("Hari is at index:", index)

Output:

Hari is at index: 2

11. Find Index of Multiple Values

names = ["Ram", "Sita", "Hari", "Sita", "Gita"]

for index, name in enumerate(names):
    if name == "Sita":
        print("Sita found at:", index)

Output:

Sita found at: 1
Sita found at: 3

12. Modify Items Using enumerate()

Suppose we want to modify values in a list.

numbers = [10, 20, 30, 40]

for index, number in enumerate(numbers):
    numbers[index] = number * 2

print(numbers)

Output:

[20, 40, 60, 80]

Here, index allows us to access and update the original list.

13. Add 10 to Every Value

marks = [50, 60, 70, 80]

for index, mark in enumerate(marks):
    marks[index] = mark + 10

print(marks)

Output:

[60, 70, 80, 90]

14. Practical Student Example

students = ["Ram", "Sita", "Hari", "Gita"]

for roll_number, student in enumerate(students, start=1):
    print(f"Roll No: {roll_number}, Name: {student}")

Output:

Roll No: 1, Name: Ram
Roll No: 2, Name: Sita
Roll No: 3, Name: Hari
Roll No: 4, Name: Gita

15. Practical Marks Example

students = ["Ram", "Sita", "Hari", "Gita"]
marks = [75, 85, 65, 90]

for index, student in enumerate(students):
    print(student, marks[index])

Output:

Ram 75
Sita 85
Hari 65
Gita 90

However, when two lists need to be processed together, zip() is often cleaner:

for student, mark in zip(students, marks):
    print(student, mark)

16. enumerate() with zip()

You can combine enumerate() and zip().

students = ["Ram", "Sita", "Hari"]
marks = [75, 85, 65]

for index, (student, mark) in enumerate(zip(students, marks), start=1):
    print(index, student, mark)

Output:

1 Ram 75
2 Sita 85
3 Hari 65

This is useful when you need:

• Serial number
• Student name
• Marks

all together.

17. Practical Product Example

products = ["Laptop", "Mouse", "Keyboard", "Monitor"]

for number, product in enumerate(products, start=1):
    print(f"{number}. {product}")

Output:

1. Laptop
2. Mouse
3. Keyboard
4. Monitor

18. Practical Course Example

courses = [
    "Python Programming",
    "Django",
    "MERN Stack",
    "Data Science",
    "Machine Learning"
]

for number, course in enumerate(courses, start=1):
    print(f"{number}. {course}")

Output:

1. Python Programming
2. Django
3. MERN Stack
4. Data Science
5. Machine Learning

19. Create a Dictionary Using enumerate()

You can use enumerate() to create numbered dictionary keys.

courses = ["Python", "Django", "MERN"]

result = {
    number: course
    for number, course in enumerate(courses, start=1)
}

print(result)

Output:

{1: 'Python', 2: 'Django', 3: 'MERN'}

This combines enumerate() with dictionary comprehension.

20. Create a List Using enumerate()

You can also create a list containing indexes and values.

names = ["Ram", "Sita", "Hari"]

result = [
    (index, name)
    for index, name in enumerate(names)
]

print(result)

Output:

[(0, 'Ram'), (1, 'Sita'), (2, 'Hari')]

21. Find Even Numbers and Their Index

numbers = [10, 15, 20, 25, 30, 35]

for index, number in enumerate(numbers):
    if number % 2 == 0:
        print(index, number)

Output:

0 10
2 20
4 30

22. Find the First Matching Item

names = ["Ram", "Sita", "Hari", "Gita"]

for index, name in enumerate(names):
    if name == "Hari":
        print("Found at index:", index)
        break

Output:

Found at index: 2

The break statement stops the loop after the first match.

23. Practical Shopping Cart Example

cart = [
    "Laptop",
    "Mouse",
    "Keyboard",
    "Monitor"
]

for number, item in enumerate(cart, start=1):
    print(f"{number}. {item}")

Output:

1. Laptop
2. Mouse
3. Keyboard
4. Monitor

24. Practical To-Do List

tasks = [
    "Learn Python",
    "Practice Django",
    "Build a project",
    "Deploy website"
]

for number, task in enumerate(tasks, start=1):
    print(f"{number}. {task}")

Output:

1. Learn Python
2. Practice Django
3. Build a project
4. Deploy website

25. enumerate() vs range(len())

Using range(len())

names = ["Ram", "Sita", "Hari"]

for i in range(len(names)):
    print(i, names[i])

Using enumerate()

names = ["Ram", "Sita", "Hari"]

for i, name in enumerate(names):
    print(i, name)

Both produce:

0 Ram
1 Sita
2 Hari

But enumerate() is generally cleaner because you don't have to manually access names[i].

26. Common Mistake

Don't do this:

names = ["Ram", "Sita", "Hari"]

for index in enumerate(names):
    print(index)

The variable index actually contains a tuple:

(0, 'Ram')
(1, 'Sita')
(2, 'Hari')

Instead, unpack the two values:

for index, name in enumerate(names):
    print(index, name)

27. Understanding What enumerate() Returns

names = ["Ram", "Sita", "Hari"]

result = enumerate(names)

print(result)

You will see something similar to:

<enumerate object at 0x...>

Like generators, enumerate() returns an iterator object.

You can convert it into a list:

names = ["Ram", "Sita", "Hari"]

result = list(enumerate(names))

print(result)

Output:

[(0, 'Ram'), (1, 'Sita'), (2, 'Hari')]

28. enumerate() with a Generator

enumerate() can work with any iterable, including generators.

numbers = (
    x ** 2
    for x in range(1, 6)
)

for index, number in enumerate(numbers, start=1):
    print(index, number)

Output:

1 1
2 4
3 9
4 16
5 25

This is a good example of combining the previous topic with the current one.

29. Practical Data Processing Example

employees = [
    {"name": "Ram", "salary": 35000},
    {"name": "Sita", "salary": 55000},
    {"name": "Hari", "salary": 45000}
]

for number, employee in enumerate(employees, start=1):
    print(
        number,
        employee["name"],
        employee["salary"]
    )

Output:

1 Ram 35000
2 Sita 55000
3 Hari 45000

30. Real-World Example : Display Course List

courses = [
    "Python Programming",
    "Python Django",
    "MERN Stack",
    "Data Analysis",
    "Data Science",
    "Machine Learning"
]

print("Available Courses:")

for number, course in enumerate(courses, start=1):
    print(f"{number}. {course}")

Output:

Available Courses:
1. Python Programming
2. Python Django
3. MERN Stack
4. Data Analysis
5. Data Science
6. Machine Learning

Important Points to Remember

Basic syntax

enumerate(iterable)

With starting position

enumerate(iterable, start=1)

Common usage

for index, value in enumerate(data):
    print(index, value)

Start from 1

for number, value in enumerate(data, start=1):
    print(number, value)

enumerate() returns

An enumerate iterator containing pairs of:

(index, value)

Main advantage

Instead of:

for i in range(len(items)):
    print(i, items[i])

you can write:

for i, item in enumerate(items):
    print(i, item)

Easy way to remember

enumerate()
     ↓
index + value
     ↓
(index, value)