While Loops, For Loops & Range

while repeats a block while a condition is True. Watch for infinite loops — update the condition inside.

Python While Loops

while repeats a block while a condition is True. Watch for infinite loops — update the condition inside.

break exits the loop; continue skips to the next iteration.

Real-life example: while is like stirring soup until it boils — keep going until the condition changes.

Countdown

count = 3
while count > 0:
    print(count)
    count -= 1
print("Go!")

for item in iterable loops over lists, strings, dicts, and more. Prefer for when you know what you are iterating.

Use enumerate() when you need both index and value.

Real-life example: for is like checking each student in a roll call — one name at a time until the list ends.

Loop over a list

topics = ["syntax", "loops", "functions"]
for i, topic in enumerate(topics, start=1):
    print(i, topic.title())

range(stop), range(start, stop), range(start, stop, step) generate number sequences without storing a full list.

Common pattern: for i in range(5):

Real-life example: range is a numbered ticket dispenser — it hands you 0, 1, 2… without printing all tickets at once.

range examples

print(list(range(5)))
print(list(range(2, 10, 2)))