Enumerate
Getting index and value in loops
Interview Relevant: Pythonic iteration
Enumerate
Get index and value when iterating.
Code Examples
Using enumerate for indexed iteration.
python
1fruits = ['apple', 'banana', 'cherry']
2
3# Without enumerate (avoid this)
4for i in range(len(fruits)):
5 print(i, fruits[i])
6
7# With enumerate (Pythonic!)
8for i, fruit in enumerate(fruits):
9 print(i, fruit)
10
11# Start from different index
12for i, fruit in enumerate(fruits, start=1):
13 print(i, fruit) # 1 apple, 2 banana, 3 cherry
14
15# enumerate returns iterator
16list(enumerate(fruits))
17# [(0, 'apple'), (1, 'banana'), (2, 'cherry')]
18
19# Use in list comprehension
20indexed = [(i, x) for i, x in enumerate(fruits)]