Iteration

Ranges objects are sequences of integers that you can iterate over.

from arranges import Ranges

assert list(Ranges("start:3, 10")) == [0, 1, 2, 10]

Cardinality of the address range

The length of a range is the number of elements it contains. But because ranges can be boundless, we have a special inf value that represents an infinite int as Python doesn’t have or support one.

This value is math.inf, but when returned from len it becomes sys.maxsize as it only supports ints that are this size or smaller. When comparing inf to sys.maxsize it’ll return True, but this doesn’t work in all directions:

import math
import sys
from arranges import Ranges, inf

assert len(Ranges("1,2,3,4,10:20")) == 14

full = Ranges(":")

assert len(full) == sys.maxsize
assert len(full) == inf
assert sys.maxsize == inf
assert full.stop == inf
assert inf - 100 == sys.maxsize

# Careful though, this does not hold
assert len(full) != math.inf

# because it's an int
assert type(len(full)) is int

Truthyness

Empty ranges are, of course, Falsey.

from arranges import Ranges

assert Ranges(":")
assert Range(10)

assert not Ranges("")