Python Loops

for Loop

A for loop iterates over any sequence: a list, string, range, dict and so on.

Python
for i in range(1, 6):
    print(i, "squared is", i * i)
1 squared is 1 2 squared is 4 3 squared is 9 4 squared is 16 5 squared is 25

range(start, stop, step) goes up to stop − 1.

while Loop

Python
n, rev = 1234, 0
while n > 0:
    rev = rev * 10 + n % 10
    n //= 10
print("Reversed:", rev)
Reversed: 4321

break, continue and loop-else

Python
for n in range(2, 20):
    for d in range(2, n):
        if n % d == 0:
            break          # not prime
    else:
        print(n, end=" ")  # runs only if loop didn't break
2 3 5 7 11 13 17 19

enumerate and zip

Python
names = ["Asha", "Ravi"]
marks = [88, 76]
for i, (n, m) in enumerate(zip(names, marks), start=1):
    print(i, n, m)
1 Asha 88 2 Ravi 76
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