for Loop (Iteration)

The for loop iterates over items of any iterable (string, list, tuple, dict, range, set) — unlike C's counter-based for loop.

Syntax

for item in iterable:
    statement(s)

for ch in "Python":
    print(ch)

Output:

P
y
t
h
o
n

Using range()

range(start, stop, step) generates a sequence of numbers (stop is excluded).

for i in range(5):          # 0,1,2,3,4
    print(i)

for i in range(1, 6):       # 1,2,3,4,5
    print(i)

for i in range(10, 0, -2):  # 10,8,6,4,2
    print(i)

Iterating over a list

fruits = ["apple", "banana", "mango"]
for fruit in fruits:
    print(fruit)

Iterating with index — enumerate()

for index, fruit in enumerate(fruits):
    print(index, fruit)
# 0 apple
# 1 banana
# 2 mango

Iterating over a dictionary

student = {"name": "Riya", "age": 21}
for key in student:
    print(key, ":", student[key])

for key, value in student.items():
    print(key, "->", value)

for-else

The else block runs only if the loop completes without a break.

for i in range(5):
    print(i)
else:
    print("Loop finished normally")

Flowchart