37 lines
1.1 KiB
Python
37 lines
1.1 KiB
Python
# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import logging
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LOG = logging.getLogger(__name__)
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def unique(iterator):
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"""Iterator that only returns unique values from its input.
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A worst-case version of this ends up storing all of the data from
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the iterator in memory to check for unique values.
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The values from the iterator must be hashable.
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:param iterator: iterable of hashable data to consume
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:returns: generator
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"""
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seen = set()
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for i in iterator:
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if i in seen:
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LOG.debug('ignoring duplicate %r', i)
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continue
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yield i
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seen.add(i)
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