Mercurial > hg > config
annotate python/base_encode.py @ 749:f7b939206baf
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| author | Jeff Hammel <k0scist@gmail.com> |
|---|---|
| date | Tue, 30 Jun 2015 15:22:21 -0700 |
| parents | 9c2a18033128 |
| children |
| rev | line source |
|---|---|
|
729
fc4749433229
https://gist.github.com/adyliu/4494223
Jeff Hammel <k0scist@gmail.com>
parents:
diff
changeset
|
1 #!/usr/bin/env python |
|
fc4749433229
https://gist.github.com/adyliu/4494223
Jeff Hammel <k0scist@gmail.com>
parents:
diff
changeset
|
2 #-*- coding:utf-8 -*- |
| 730 | 3 |
| 4 """ | |
| 5 arbitrary base encoding tools (convert number <=> string) | |
| 6 | |
| 7 modified from | |
| 8 https://gist.github.com/adyliu/4494223 | |
| 9 """ | |
| 10 | |
| 11 import argparse | |
| 12 import string | |
|
729
fc4749433229
https://gist.github.com/adyliu/4494223
Jeff Hammel <k0scist@gmail.com>
parents:
diff
changeset
|
13 import sys |
| 730 | 14 |
| 15 basedigits = string.digits + string.letters | |
| 16 | |
| 17 def decode(s, basedigits=basedigits): | |
| 18 | |
| 19 BASE = len(basedigits) | |
| 20 ret,mult = 0,1 | |
| 21 for c in reversed(s): | |
| 22 ret += mult*basedigits.index(c) | |
| 23 mult *= BASE | |
| 24 return ret | |
| 25 | |
| 26 def encode(num, basedigits=basedigits): | |
| 27 BASE = len(basedigits) | |
| 28 | |
| 29 if num < 0: | |
| 30 raise Exception("positive number "+num) | |
| 31 if num == 0: | |
| 32 return '0' | |
| 33 ret='' | |
| 34 while num: | |
| 35 ret = (basedigits[num%BASE])+ret | |
| 36 num = int(num/BASE) | |
| 37 return ret | |
| 38 | |
| 39 | |
| 40 def main(args=sys.argv[1:]): | |
| 41 | |
| 42 parser = argparse.ArgumentParser(description=__doc__) | |
| 43 parser.add_argument('num', nargs='+', | |
| 44 help="num") | |
| 45 parser.add_argument('-b', '--base', dest='base', | |
| 46 type=int, default=32, | |
| 47 help="base to use [DEFAULT: %(default)s]") | |
| 48 parser.add_argument('-c', '--chars', '--base-digits', dest='basedigits', | |
| 49 default=globals()['basedigits'], | |
| 50 help="base digits [DEFAULT: %(default)s]") | |
| 51 options = parser.parse_args(args) | |
| 52 | |
| 53 # determine base digits | |
| 54 basedigits = options.basedigits[:options.base] | |
| 55 base = len(basedigits) | |
| 56 | |
| 57 for num in options.num: | |
| 58 | |
| 59 try: | |
| 60 num = int(num) | |
| 61 encoded = encode(num, basedigits) | |
| 62 print ('ENCODE base {}: {}->{} [{}]'.format(base, num, encoded, len(encoded))) | |
| 63 except ValueError: | |
| 64 print ('%*s %s %s' % ('DECODE', num, decode(num))) | |
| 65 | |
|
729
fc4749433229
https://gist.github.com/adyliu/4494223
Jeff Hammel <k0scist@gmail.com>
parents:
diff
changeset
|
66 if __name__ == '__main__': |
| 730 | 67 main() |