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1# This file is part of pex_config. 

2# 

3# Developed for the LSST Data Management System. 

4# This product includes software developed by the LSST Project 

5# (http://www.lsst.org). 

6# See the COPYRIGHT file at the top-level directory of this distribution 

7# for details of code ownership. 

8# 

9# This software is dual licensed under the GNU General Public License and also 

10# under a 3-clause BSD license. Recipients may choose which of these licenses 

11# to use; please see the files gpl-3.0.txt and/or bsd_license.txt, 

12# respectively. If you choose the GPL option then the following text applies 

13# (but note that there is still no warranty even if you opt for BSD instead): 

14# 

15# This program is free software: you can redistribute it and/or modify 

16# it under the terms of the GNU General Public License as published by 

17# the Free Software Foundation, either version 3 of the License, or 

18# (at your option) any later version. 

19# 

20# This program is distributed in the hope that it will be useful, 

21# but WITHOUT ANY WARRANTY; without even the implied warranty of 

22# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

23# GNU General Public License for more details. 

24# 

25# You should have received a copy of the GNU General Public License 

26# along with this program. If not, see <http://www.gnu.org/licenses/>. 

27 

28__all__ = ["ChoiceField"] 

29 

30from .config import Field, _typeStr 

31from .callStack import getStackFrame 

32 

33 

34class ChoiceField(Field): 

35 """A configuration field (`~lsst.pex.config.Field` subclass) that allows a 

36 user to select from a predefined set of values. 

37 

38 Use ``ChoiceField`` when a configuration can only take one of a predefined 

39 set of values. Each choice must be of the same type. 

40 

41 Parameters 

42 ---------- 

43 doc : `str` 

44 Documentation string that describes the configuration field. 

45 dtype : class 

46 The type of the field's choices. For example, `str` or `int`. 

47 allowed : `dict` 

48 The allowed values. Keys are the allowed choices (of ``dtype``-type). 

49 Values are descriptions (`str`-type) of each choice. 

50 default : ``dtype``-type, optional 

51 The default value, which is of type ``dtype`` and one of the allowed 

52 choices. 

53 optional : `bool`, optional 

54 If `True`, this configuration field is *optional*. Default is `True`. 

55 deprecated : None or `str`, optional 

56 A description of why this Field is deprecated, including removal date. 

57 If not None, the string is appended to the docstring for this Field. 

58 

59 See also 

60 -------- 

61 ConfigChoiceField 

62 ConfigDictField 

63 ConfigField 

64 ConfigurableField 

65 DictField 

66 Field 

67 ListField 

68 RangeField 

69 RegistryField 

70 """ 

71 def __init__(self, doc, dtype, allowed, default=None, optional=True, deprecated=None): 

72 self.allowed = dict(allowed) 

73 if optional and None not in self.allowed: 73 ↛ 76line 73 didn't jump to line 76, because the condition on line 73 was never false

74 self.allowed[None] = "Field is optional" 

75 

76 if len(self.allowed) == 0: 76 ↛ 77line 76 didn't jump to line 77, because the condition on line 76 was never true

77 raise ValueError("ChoiceFields must allow at least one choice") 

78 

79 Field.__init__(self, doc=doc, dtype=dtype, default=default, 

80 check=None, optional=optional, deprecated=deprecated) 

81 

82 self.__doc__ += "\n\nAllowed values:\n\n" 

83 for choice, choiceDoc in self.allowed.items(): 

84 if choice is not None and not isinstance(choice, dtype): 84 ↛ 85line 84 didn't jump to line 85, because the condition on line 84 was never true

85 raise ValueError("ChoiceField's allowed choice %s is of incorrect type %s. Expected %s" % 

86 (choice, _typeStr(choice), _typeStr(dtype))) 

87 self.__doc__ += "%s\n %s\n" % ('``{0!r}``'.format(str(choice)), choiceDoc) 

88 

89 self.source = getStackFrame() 

90 

91 def _validateValue(self, value): 

92 Field._validateValue(self, value) 

93 if value not in self.allowed: 

94 msg = "Value {} is not allowed.\n" \ 

95 "\tAllowed values: [{}]".format(value, ", ".join(str(key) for key in self.allowed)) 

96 raise ValueError(msg)