add from/to26 functions

This commit is contained in:
j 2011-09-30 23:42:56 +02:00
parent 40b3dabb99
commit e77d0c9de1

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@ -4,6 +4,42 @@ import math
import re import re
import string import string
def to26(q):
"""
Converts an integer to base 32
We exclude 4 of the 26 letters: I L O U.
http://www.crockford.com/wrmg/base32.html
>>> for i in range(0, 1000): assert from26(to26(i)) == i
>>> to26(0)
'A'
>>> to26(347485647)
'ABCDEF'
"""
if q < 0: raise ValueError, "must supply a positive integer"
base26 = string.letters[26:]
converted = []
while q != 0:
q, r = divmod(q, 26)
l = base26[r]
converted.insert(0, l)
return "".join(converted) or 'A'
def from26(q):
"""
Converts an base 26 string to an integer
>>> from32('A')
0
"""
base26 = string.letters[26:]
q = q.replace('-','')
r = 0
for i in q:
r = r * 26 + base26.index(i.upper())
return r
def to32(q): def to32(q):
""" """
Converts an integer to base 32 Converts an integer to base 32