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Python: defining regex pooling

I have a list of templates like

list_patterns = [': error:', ': warning:', 'cc1plus:', 'undefine reference to']

what I want to do is create a union of all of them, giving a regular expression that matches every element in list_patterns[but doesn't seem to match any duplicate list in path_list - msw]

re.compile(list_patterns)

Is it possible?

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6 answers

There are several ways to do this. The easiest way:

list_patterns = [': error:', ': warning:', 'cc1plus:', 'undefine reference to']
string = 'there is an : error: and a cc1plus: in this string'
print re.findall('|'.join(list_patterns), string)

Conclusion:

[': error:', 'cc1plus:']

which is great as long as the concatenation of your search patterns does not violate the regular expression (for example, if one of them contains a special regular expression character, such as an opening bracket). This can be done like this:

list_patterns = [': error:', ': warning:', 'cc1plus:', 'undefine reference to']
string = 'there is an : error: and a cc1plus: in this string'
pattern = "|".join(re.escape(p) for p in list_patterns)
print re.findall(pattern, string)

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list_regexs = [re.compile(x) for x in list_patterns]
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, ? :

': error:|: warning:|cc1plus:|undefine reference to'?

, Python:

re.compile("|".join(list_patterns))
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ptrn = re.compile('|'.join(re.escape(e) for e in list_patterns))

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+1

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:

import re

def usedgroupindex(indexabledata):
    for i,datum in enumerate(indexabledata):
        if datum: return i
    # return None

def findallstrings(list_patterns, string):
    lp = sorted(set(list_patterns), reverse=True)
    pattern = "|".join("(%s)" % re.escape(p) for p in lp)
    # for m in re.findall(pattern, string): print (m, usedgroupindex(m))
    return ( len(set(usedgroupindex(m) for m in re.findall(pattern, string)))
             == len(lp) )

list_patterns = [': error:', ': warning:', 'cc1plus:', 'undefine reference to']
string = ' XZX '.join(list_patterns)

print ( findallstrings(list_patterns, string) )
+1

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'.*?'.join(list_patterns) ( RE), , '.*?'.join(re.escape(p) for p list_patterns)).

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class relike(object):
    def __init__(self, list_patterns):
        self.relist = [re.compile(p) for p in list_patterns]
    def search(self, s):
        return all(r.search(s) for r in relist)
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