w3resource

Python: enumerate() function

enumerate() function

The enumerate() function returns an enumerate object. iterable must be a sequence, an iterator, or some other object which supports iteration.

Note: The __next__() method of the iterator returned by enumerate() returns a tuple containing a count (from start which defaults to 0) and the values obtained from iterating over iterable.

Version:

(Python 3)

Syntax:

enumerate(iterable, start=0)

Parameter:

Name Description
iterable A sequence, an iterator, or some other object which supports iteration
start A Number. Defining the start number of the enumerate object. Default 0.If start is omitted, 0 is taken as start.

Return value:

Return an enumerate object.

Example: Python enumerate() function

<<< seasons = ['Spring', 'Summer', 'Fall', 'Winter']
<<< list(enumerate(seasons))
[(0, 'Spring'), (1, 'Summer'), (2, 'Fall'), (3, 'Winter')]
<<< list(enumerate(seasons, start=1))
[(1, 'Spring'), (2, 'Summer'), (3, 'Fall'), (4, 'Winter')]

Equivalent to:

def enumerate(sequence, start=0):
    n = start
    for elem in sequence:
        yield n, elem
        n += 1

Example: Python enumerate() function

fruits = ['Mango', 'Apple', 'Orange', 'Peach']
print(list(enumerate(fruits)))
print(list(enumerate(fruits, start=1)))

Output:

[(0, 'Mango'), (1, 'Apple'), (2, 'Orange'), (3, 'Peach')]                      
[(1, 'Mango'), (2, 'Apple'), (3, 'Orange'), (4, 'Peach')]

Example:

Fruits = ['Apple', 'Mango', 'Orange']
enumerateFruits = enumerate(Fruits)

print(type(enumerateFruits))

# converting to list
print(list(enumerateFruits))

# changing the default counter
enumerateFruits = enumerate(Fruits, 10)
print(list(enumerateFruits))

Output:

<class 'enumerate'>  
[(0, 'Apple'), (1, 'Mango'), (2, 'Orange')]  [(10, 'Apple'), (11, 'Mango'), (12, 'Orange')]

Example: Looping Over an Enumerate object

Fruits = ['Apple', 'Mango', 'Orange']

for item in enumerate(Fruits):
  print(item)

print('\n')
for count, item in enumerate(Fruits):
  print(count, item)

print('\n')
# changing default start value
for count, item in enumerate(Fruits, 50):
  print(count, item)

Output:


(0, 'Apple')
(1, 'Mango')
(2, 'Orange')


0 Apple
1 Mango
2 Orange


50 Apple
51 Mango
52 Orange

Python Code Editor:

Previous: divmod()
Next: eval()

Test your Python skills with w3resource's quiz



Python: Tips of the Day

How do I check if a list is empty?

For example, if passed the following:

a = []
if not a:
  print("List is empty")

Ref: https://bit.ly/2A4JXx9