UsageΒΆ

from intspan import intspan

s = intspan('1-3,14,29,92-97')
s.discard('2,13,92')
print s
print repr(s)
print list(s)

yields:

1,3,14,29,93-97
intspan('1,3,14,29,93-97')
[1, 3, 14, 29, 93, 94, 95, 96, 97]

While:

>>> for n in intspan('1-3,5'):
>>>     print n                 # Python 2
1
2
3
5

Most set operations such as intersection, union, and so on are available just as they are in Python’s set. In addition, if you wish to extract the contiguous ranges:

>>> for r in intspan('1-3,5,7-9,10,21-22,23,24').ranges():
>>>     print r                 # Python 2
(1, 3)
(5, 5)
(7, 10)
(21, 24)

Note that these endpoints represent closed intervals, rather than the half-open intervals commonly used with Python’s range(). If you combine intspan ranges with Python generators, you’ll have to increment the stop value by one yourself to create the suitable “half-open interval.”

There is a corresponding range-oriented constructor:

>>> intspan.from_ranges([ (4,6), (10,12) ])
intspan('4-6,10-12')

A convenience from_range method creates a contiguous intspan from a given low to a high value.:

>>> intspan.from_range(8, 12)
intspan('8-12')

The universe method returns the covering set or “implied universe” of an intspan:

>> intspan('1,3,5,7').universe()
intspan('1-7')

To find the elements not included, you can use the complement method:

>>> items = intspan('1-3,5,7-9,10,21-24')
>>> items.complement()
intspan('4,6,11-20')

The “missing” elements are computed as any integers between the intspan‘s minimum and maximum values that aren’t included. If you’d like to customize the intended low and high bounds, you can give those explicitly.:

>>> items.complement(high=30)
intspan('4,6,11-20,25-30')

You can use the difference method or - operator to find the complement with respect to an arbitrary set, rather than just an expected contiguous range.