| 1 | import re, string
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| 2 | # Taken from http://effbot.org/zone/python-replace.htm
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| 3 |
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| 4 | class MultiReplace:
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| 5 | def __init__(self, repl_dict):
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| 6 | # "compile" replacement dictionary
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| 7 |
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| 8 | # assume char to char mapping
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| 9 | charmap = map(chr, range(256))
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| 10 | for k, v in repl_dict.items():
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| 11 | if len(k) != 1 or len(v) != 1:
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| 12 | self.charmap = None
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| 13 | break
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| 14 | charmap[ord(k)] = v
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| 15 | else:
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| 16 | self.charmap = string.join(charmap, "")
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| 17 | return
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| 18 |
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| 19 | # string to string mapping; use a regular expression
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| 20 | keys = repl_dict.keys()
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| 21 | keys.sort() # lexical order
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| 22 | keys.reverse() # use longest match first
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| 23 | pattern = string.join(map(re.escape, keys), "|")
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| 24 | self.pattern = re.compile(pattern)
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| 25 | self.dict = repl_dict
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| 26 |
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| 27 | def replace(self, str):
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| 28 | # apply replacement dictionary to string
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| 29 | if self.charmap:
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| 30 | return string.translate(str, self.charmap)
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| 31 | def repl(match, get=self.dict.get):
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| 32 | item = match.group(0)
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| 33 | return get(item, item)
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| 34 | return self.pattern.sub(repl, str)
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| 35 |
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| 36 | #print r.replace("spam&eggs") # prints "eggs&spam"
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| 37 | #
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| 38 | #r = MultiReplace({"a": "b", "b": "a"})
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| 39 | #print r.replace("keaba") # "kebab"
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| 40 | #
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| 41 | #r = MultiReplace({". ": "\n", "!": "exclamation", "?": "question"})
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| 42 | #print repr(r.replace("look. an albatross !")) # 'look\nan albatross exclamation'
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