Python ยท Chapter 14 of 45
Python For Loop
`for` iterates over any sequence: list, tuple, string, range, dict keys, or any iterable.
Use `range(n)` to loop a fixed number of times.
range() variants
`range(stop)`, `range(start, stop)`, `range(start, stop, step)`. Stop is exclusive.
Looping with index
Use `enumerate(seq)` when you need both the index and the value.
Example 1 (python)
for fruit in ["apple", "banana", "cherry"]:
print(fruit)Output
apple
banana
cherryIterates over each item in the list.
Example 2 (python)
for i, name in enumerate(["Ana", "Ben"], start=1):
print(i, name)Output
1 Ana
2 Benenumerate gives (index, value) pairs.
Key points
- Iterates over any iterable.
- `range(n)` produces 0 to n-1.
- Use `enumerate()` for (index, value).
- Use `zip()` to loop over multiple sequences in parallel.
๐ก Note: Never modify a list while iterating over it โ copy it first: `for x in mylist[:]`.