Enumerate() in Python

Often, when dealing with iterators, we also get need to keep a count of iterations. Python eases the programmers’ task by providing a built-in function enumerate() for this task. Enumerate() method adds a counter to an iterable and returns it in a form of enumerating object. This enumerated object can then be used directly for loops or converted into a list of tuples using the list() function.

Syntax:

enumerate(iterable, start=0)

Parameters:

• Iterable: any object that supports iteration
• Start: the index value from which the counter is to be started, by default it is 0

Example

Python3

# Python program to illustrate
# enumerate function
l1 = ["eat", "sleep", "repeat"]
s1 = "geek"

# creating enumerate objects
obj1 = enumerate(l1)
obj2 = enumerate(s1)

print ("Return type:", type(obj1))
print (list(enumerate(l1)))

# changing start index to 2 from 0
print (list(enumerate(s1, 2)))

Output:

Return type: 
[(0, 'eat'), (1, 'sleep'), (2, 'repeat')]
[(2, 'g'), (3, 'e'), (4, 'e'), (5, 'k')]

Using Enumerate object in loops:

Python3

# Python program to illustrate
# enumerate function in loops
l1 = ["eat", "sleep", "repeat"]

# printing the tuples in object directly
for ele in enumerate(l1):
    print (ele)

# changing index and printing separately
for count, ele in enumerate(l1, 100):
    print (count, ele)

# getting desired output from tuple
for count, ele in enumerate(l1):
    print(count)
    print(ele)

Output:

(0, 'eat')
(1, 'sleep')
(2, 'repeat')
100 eat
101 sleep
102 repeat
0
eat
1
sleep
2
repeat

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