55 lines
1.6 KiB
Python
55 lines
1.6 KiB
Python
#
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# Copyright (c) 2012 Helmut Merz helmutm@cy55.de
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#
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"""
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Iterator and generator utilities.
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"""
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from itertools import islice
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class BatchIterator(object):
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def __init__(self, data, limit=20, start=0):
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self.data = iter(data)
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self.limit = limit
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self.start = start
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self.count = 0
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self.batch = 0
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self.exhausted = False
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def __iter__(self):
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return self
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def next(self):
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if self.count >= (self.batch + 1) * self.limit:
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raise StopIteration
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if self.start:
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for i in islice(self.data, 0, self.start*self.limit):
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pass
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self.start = 0
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self.count += 1
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try:
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return self.data.next()
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except StopIteration:
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self.exhausted = True
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raise
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def advance(self, batches=1):
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self.batch += batches
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return not self.exhausted
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