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range()

range

An immutable sequence of integers: it does not hold all the numbers in memory but computes them on the fly. Used in for loops and in slices.

Syntax

range(stop) | range(start, stop) | range(start, stop, step)

range is not a generator but a full immutable sequence: you can index it, slice it, call len() on it and iterate over it as many times as you like (a generator would be exhausted after the first pass). And x in range(...) with an integer runs in O(1) — Python does the arithmetic instead of scanning every number.

Examples

print(list(range(5)))  # → [0, 1, 2, 3, 4]
print(list(range(2, 8)))  # → [2, 3, 4, 5, 6, 7]
print(list(range(0, 10, 2)))  # → [0, 2, 4, 6, 8]
print(list(range(10, 0, -2)))  # → [10, 8, 6, 4, 2]
print(list(range(5, 5)))  # → [] (пустой при start==stop)
print(list(range(-3, 3)))  # → [-3, -2, -1, 0, 1, 2]
print(sum(range(101)))  # → 5050 (сумма 1..100)
for i in range(3, 0, -1):
    print(i, end=" ")  # → 3 2 1

range()

Syntax

Examples

See also