cpython/Doc/tools/roman.py
Georg Brandl a3c242c19d Merged revisions 72558,72745,72750,72876,73042,73045-73048,73069,73089,73163,73186,73213,73215,73217,73257-73258,73260 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

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  r72558 | benjamin.peterson | 2009-05-11 01:52:09 +0200 (Mo, 11 Mai 2009) | 1 line

  sys.setdefaultencoding() strikes me as a bad example
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  r72745 | benjamin.peterson | 2009-05-17 16:16:29 +0200 (So, 17 Mai 2009) | 1 line

  ignore .rst files in sphinx its self
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  r72750 | benjamin.peterson | 2009-05-17 18:59:27 +0200 (So, 17 Mai 2009) | 1 line

  chop off slash
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  r72876 | benjamin.peterson | 2009-05-23 22:59:09 +0200 (Sa, 23 Mai 2009) | 1 line

  remove mention of old ctypes version
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  r73042 | benjamin.peterson | 2009-05-30 05:10:52 +0200 (Sa, 30 Mai 2009) | 1 line

  no fdatasync on macos
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  r73045 | georg.brandl | 2009-05-30 09:26:04 +0200 (Sa, 30 Mai 2009) | 1 line

  #6146: fix markup bug.
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  r73046 | georg.brandl | 2009-05-30 09:31:25 +0200 (Sa, 30 Mai 2009) | 1 line

  Use preferred form of raising exceptions.
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  r73047 | georg.brandl | 2009-05-30 12:33:23 +0200 (Sa, 30 Mai 2009) | 1 line

  Fix some more small markup problems.
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  r73048 | georg.brandl | 2009-05-30 12:34:25 +0200 (Sa, 30 Mai 2009) | 1 line

  Fix markup problem.
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  r73069 | benjamin.peterson | 2009-05-31 02:42:42 +0200 (So, 31 Mai 2009) | 1 line

  fix signature
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  r73089 | andrew.kuchling | 2009-06-01 02:14:19 +0200 (Mo, 01 Jun 2009) | 1 line

  The class for regexes isn't called RegexObject any more; correct the text
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  r73163 | georg.brandl | 2009-06-03 09:25:35 +0200 (Mi, 03 Jun 2009) | 1 line

  Use the preferred form of raise statements in the docs.
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  r73186 | georg.brandl | 2009-06-03 23:21:09 +0200 (Mi, 03 Jun 2009) | 1 line

  #6174: fix indentation in code example.
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  r73213 | georg.brandl | 2009-06-04 12:15:57 +0200 (Do, 04 Jun 2009) | 1 line

  #5967: note that the C slicing APIs do not support negative indices.
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  r73215 | georg.brandl | 2009-06-04 12:22:31 +0200 (Do, 04 Jun 2009) | 1 line

  #6176: fix man page section for flock(2).
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  r73217 | georg.brandl | 2009-06-04 12:27:21 +0200 (Do, 04 Jun 2009) | 1 line

  #6175: document that inet_aton supports alternate input formats with less than three dots.
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  r73257 | georg.brandl | 2009-06-06 19:50:05 +0200 (Sa, 06 Jun 2009) | 1 line

  #6211: elaborate a bit on ways to call the function.
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  r73258 | georg.brandl | 2009-06-06 19:51:31 +0200 (Sa, 06 Jun 2009) | 1 line

  #6204: use a real reference instead of "see later".
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  r73260 | georg.brandl | 2009-06-06 20:21:58 +0200 (Sa, 06 Jun 2009) | 1 line

  #6224: s/JPython/Jython/, and remove one link to a module nine years old.
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2009-10-27 14:19:50 +00:00

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Python

"""Convert to and from Roman numerals"""
__author__ = "Mark Pilgrim (f8dy@diveintopython.org)"
__version__ = "1.4"
__date__ = "8 August 2001"
__copyright__ = """Copyright (c) 2001 Mark Pilgrim
This program is part of "Dive Into Python", a free Python tutorial for
experienced programmers. Visit http://diveintopython.org/ for the
latest version.
This program is free software; you can redistribute it and/or modify
it under the terms of the Python 2.1.1 license, available at
http://www.python.org/2.1.1/license.html
"""
import re
#Define exceptions
class RomanError(Exception): pass
class OutOfRangeError(RomanError): pass
class NotIntegerError(RomanError): pass
class InvalidRomanNumeralError(RomanError): pass
#Define digit mapping
romanNumeralMap = (('M', 1000),
('CM', 900),
('D', 500),
('CD', 400),
('C', 100),
('XC', 90),
('L', 50),
('XL', 40),
('X', 10),
('IX', 9),
('V', 5),
('IV', 4),
('I', 1))
def toRoman(n):
"""convert integer to Roman numeral"""
if not (0 < n < 5000):
raise OutOfRangeError("number out of range (must be 1..4999)")
if int(n) != n:
raise NotIntegerError("decimals can not be converted")
result = ""
for numeral, integer in romanNumeralMap:
while n >= integer:
result += numeral
n -= integer
return result
#Define pattern to detect valid Roman numerals
romanNumeralPattern = re.compile("""
^ # beginning of string
M{0,4} # thousands - 0 to 4 M's
(CM|CD|D?C{0,3}) # hundreds - 900 (CM), 400 (CD), 0-300 (0 to 3 C's),
# or 500-800 (D, followed by 0 to 3 C's)
(XC|XL|L?X{0,3}) # tens - 90 (XC), 40 (XL), 0-30 (0 to 3 X's),
# or 50-80 (L, followed by 0 to 3 X's)
(IX|IV|V?I{0,3}) # ones - 9 (IX), 4 (IV), 0-3 (0 to 3 I's),
# or 5-8 (V, followed by 0 to 3 I's)
$ # end of string
""" ,re.VERBOSE)
def fromRoman(s):
"""convert Roman numeral to integer"""
if not s:
raise InvalidRomanNumeralError('Input can not be blank')
if not romanNumeralPattern.search(s):
raise InvalidRomanNumeralError('Invalid Roman numeral: %s' % s)
result = 0
index = 0
for numeral, integer in romanNumeralMap:
while s[index:index+len(numeral)] == numeral:
result += integer
index += len(numeral)
return result