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# Copyright 2011 GRNET S.A. All rights reserved.
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# 
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# Redistribution and use in source and binary forms, with or
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# without modification, are permitted provided that the following
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# conditions are met:
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# 
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#   1. Redistributions of source code must retain the above
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#      copyright notice, this list of conditions and the following
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#      disclaimer.
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# 
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#   2. Redistributions in binary form must reproduce the above
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#      copyright notice, this list of conditions and the following
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#      disclaimer in the documentation and/or other materials
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#      provided with the distribution.
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# 
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# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
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# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
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# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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# POSSIBILITY OF SUCH DAMAGE.
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# 
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# The views and conclusions contained in the software and
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# documentation are those of the authors and should not be
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# interpreted as representing official policies, either expressed
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# or implied, of GRNET S.A.
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import re
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import operator
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_regexfilter = re.compile('(!?)\s*(\S+?)\s*(?:(=|!=|<=|>=|<|>)\s*(\S*?)\s*)?$', re.UNICODE)
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OPERATORS = {'=':operator.eq,
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             '!=':operator.ne,
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             '<=':operator.le,
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             '>=':operator.ge,
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             '<':operator.lt,
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             '>':operator.gt
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}
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def parse_filters(terms):
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    included = []
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    excluded = []
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    opers = []
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    match = _regexfilter.match
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    for term in terms:
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        m = match(term)
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        if m is None:
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            continue
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        neg, key, op, value = m.groups()
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        if neg:
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            excluded.append(key)
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        elif op:
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            opers.append((key, op, value))
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        elif not value:
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            included.append(key)
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    return included, excluded, opers