Coverage for python / lsst / daf / butler / utils.py: 36%

1# This file is part of daf_butler. 

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/>. 

27from __future__ import annotations 

28 

29__all__ = ( 

30 "stripIfNotNone", 

31 "transactional", 

32) 

33 

34import fnmatch 

35import functools 

36import logging 

37import re 

38from collections.abc import Callable, Iterable 

39from re import Pattern 

40from types import EllipsisType 

41from typing import Any, TypeVar 

42 

43from lsst.utils.iteration import ensure_iterable 

44 

45_LOG = logging.getLogger(__name__) 

46 

47 

48F = TypeVar("F", bound=Callable) 

49 

50 

51def transactional(func: F) -> F: 

52 """Decorate a method and makes it transactional. 

53 

54 This depends on the class also defining a ``transaction`` method 

55 that takes no arguments and acts as a context manager. 

56 

57 Parameters 

58 ---------- 

59 func : `~collections.abc.Callable` 

60 Method to decorate. 

61 

62 Returns 

63 ------- 

64 decorated : `~collections.abc.Callable` 

65 The decorated method. 

66 """ 

67 

68 @functools.wraps(func) 

69 def inner(self: Any, *args: Any, **kwargs: Any) -> Any: 

70 with self.transaction(): 

71 return func(self, *args, **kwargs) 

72 

73 return inner # type: ignore 

74 

75 

76def stripIfNotNone(s: str | None) -> str | None: 

77 """Strip leading and trailing whitespace if the given object is not None. 

78 

79 Parameters 

80 ---------- 

81 s : `str`, optional 

82 Input string. 

83 

84 Returns 

85 ------- 

86 r : `str` or `None` 

87 A string with leading and trailing whitespace stripped if ``s`` is not 

88 `None`, or `None` if ``s`` is `None`. 

89 """ 

90 if s is not None: 

91 s = s.strip() 

92 return s 

93 

94 

95def globToRegex(expressions: str | EllipsisType | None | Iterable[str]) -> list[str | Pattern] | EllipsisType: 

96 """Translate glob-style search terms to regex. 

97 

98 If a stand-alone '``*``' is found in ``expressions``, or expressions is 

99 empty or `None`, then the special value ``...`` will be returned, 

100 indicating that any string will match. 

101 

102 Parameters 

103 ---------- 

104 expressions : `str` or `~collections.abc.Iterable` [`str`] 

105 A list of glob-style pattern strings to convert. 

106 

107 Returns 

108 ------- 

109 expressions : `list` [`str` or `re.Pattern`] or ``...`` 

110 A list of regex Patterns or simple strings. Returns ``...`` if 

111 the provided expressions would match everything. 

112 """ 

113 if expressions is ... or expressions is None: 

114 return ... 

115 expressions = list(ensure_iterable(expressions)) 

116 if not expressions or "*" in expressions: 

117 return ... 

118 

119 # List of special glob characters supported by fnmatch. 

120 # See: https://docs.python.org/3/library/fnmatch.html 

121 # The complication is that "[" on its own is not a glob 

122 # unless there is a match "]". 

123 magic = re.compile(r"[\*\?]|\[.*\]|\[!.*\]") 

124 

125 # Try not to convert simple string to a regex. 

126 results: list[str | Pattern] = [] 

127 for e in expressions: 

128 res: str | Pattern 

129 if magic.search(e): 

130 res = re.compile(fnmatch.translate(e)) 

131 else: 

132 res = e 

133 results.append(res) 

134 return results 

135 

136 

137def has_globs(expressions: str | EllipsisType | None | Iterable[str]) -> bool: 

138 """Determine if the expressions have any glob wildcard characters. 

139 

140 Parameters 

141 ---------- 

142 expressions : `str` or `~collections.abc.Iterable` [`str`] 

143 A list of glob-style pattern strings to check. 

144 

145 Returns 

146 ------- 

147 has_globs : `bool` 

148 `True` if any of the supplied strings contain glob patterns. 

149 """ 

150 expanded = globToRegex(expressions) 

151 if expanded is ...: 

152 return True 

153 

154 for result in expanded: 

155 if not isinstance(result, str): 

156 return True 

157 return False 

158 

159 

160class _Marker: 

161 """Private class to use as a default value when you want to know that 

162 a default parameter has been over-ridden. 

163 """ 

164 

165 

166_DefaultMarker = _Marker() 

167"""Default value to give to a parameter when you want to know if the value 

168has been over-ridden. 

169"""