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for Loops

beginner10 min readLesson 20 of 169

Walk collections with for โ€” and the rules of the loop block.

Loops repeat work โ€” the difference between typing 100 print statements and one.

for: walk a collection

fruits = ["apple", "pear", "plum"]
for fruit in fruits:
    print(f"today: {fruit}")

Read it as a sentence: "for each fruit in fruits, do the indented block". The loop variable (fruit) takes each value in turn. Note: fruit sensibly singular vs fruits plural โ€” name loop variables like you mean it.

Strings are walkable too

for ch in "abc":
    print(ch)      # a, b, c

Indentation again

The indented block runs once per item. Dedent to run after the loop:

for fruit in fruits:
    print(fruit)
print("done")      # runs once, after all fruit

Now practice

for-Loop DrillsWalk collections and produce output per item.3 challenges ยท ยท ~30 min