lsst.daf.persistence  14.0-14-g87d16e8+8
butlerFactory.py
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1 #!/usr/bin/env python
2 
3 #
4 # LSST Data Management System
5 # Copyright 2008, 2009, 2010 LSST Corporation.
6 #
7 # This product includes software developed by the
8 # LSST Project (http://www.lsst.org/).
9 #
10 # This program is free software: you can redistribute it and/or modify
11 # it under the terms of the GNU General Public License as published by
12 # the Free Software Foundation, either version 3 of the License, or
13 # (at your option) any later version.
14 #
15 # This program is distributed in the hope that it will be useful,
16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 # GNU General Public License for more details.
19 #
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21 # the GNU General Public License along with this program. If not,
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23 #
24 
25 # -*- python -*-
26 
27 """This module defines the ButlerFactory class."""
28 from builtins import object
29 
30 from lsst.daf.persistence import Butler
31 
32 
33 class ButlerFactory(object):
34  """ButlerFactory creates data Butlers containing data mappers. Use of it
35  is deprecated in favor of the direct Butler constructor.
36 
37  The ButlerFactory class takes a mapper for a data collection.
38  It can then create Butlers with these mappers.
39 
40  A data identifier is a dictionary. The keys match those understood by a
41  mapper; the values select particular data sets or collections of data
42  sets. For example, one key might be "visit". Specifying a value of
43  "695934" for this key might select a collection of images.
44 
45  The mappers perform four functions:
46  1. Determine what keys are valid for dataset ids.
47  2. Obtain a collection of potential dataset ids matching a
48  partial dataset id.
49  3. Map a dataset id to the location of the dataset, including its
50  C++ and Python types.
51  4. Manipulate a retrieved dataset object so that it conforms to a
52  standard.
53 
54  Public methods:
55 
56  __init__(self, mapper)
57 
58  create(self)
59  """
60 
61  def __init__(self, mapper):
62  """Construct a ButlerFactory.
63 
64  @param mapper mapper object.
65  """
66 
67  self.mapper = mapper
68 
69  def create(self):
70  """Create a Butler.
71 
72  @returns a new Butler.
73  """
74 
75  if hasattr(self.mapper, 'root'):
76  root = self.mapper.root
77  else:
78  root = None
79  return Butler(root=root, mapper=self.mapper)