Python's loops are designed to iterate over iterables (collections) directly, rather than manipulating index counters — making them clean and readable. The two loop types are for and while.
fruit [, , ]:
(fruit)
fruits = [, ]
i ((fruits)):
(fruits[i])
Python's for iterates over the elements themselves — no manual indexing needed. This is cleaner and less error-prone than index-based loops.
# range — generate numbers
for i in range(5): # 0,1,2,3,4
for i in range(2, 10, 2): # 2,4,6,8 (start, stop, step)
# enumerate — when you DO need the index AND the item
for i, fruit in enumerate(fruits):
print(f"{i}: {fruit}")
# zip — iterate multiple sequences in parallel
for name, age in zip(names, ages):
print(f"{name} is {age}")
# dict iteration
for key, value in user.items():
print(key, value)
enumerate (index + item) and zip (parallel iteration) replace clumsy index manipulation — use them instead of range(len(...)).
while condition:
do_work()
if done: break # exit the loop
if skip: continue # jump to the next iteration
for item in items:
if item == target:
break
else:
# runs ONLY if the loop completed WITHOUT a break
print("not found")
The else on a loop runs if it finished normally (no break) — handy for search patterns.
Python's iteration model — looping directly over items rather than indices — is core to writing readable, idiomatic code.
Knowing the right tools (enumerate when you need indices, zip for parallel iteration, range for counts, .items() for dicts) lets you avoid the error-prone range(len(...)) anti-pattern that beginners coming from other languages often write.
Clean iteration is a hallmark of Pythonic code, and these helpers are used in nearly every program.
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