Coverage for python/lsst/meas/transiNet/modelPackages/utils.py: 26%

1# This file is part of meas_transiNet. 

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

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

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

12# (at your option) any later version. 

13# 

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

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

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

17# GNU General Public License for more details. 

18# 

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

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

21 

22__all__ = ["import_model"] 

23 

24import importlib 

25import importlib.abc 

26import importlib.machinery 

27import importlib.util 

28import torch.nn 

29 

30 

31def load_module_from_memory(file_like_object, name='model'): 

32 """Load a module from the specified file-like object. 

33 

34 Parameters 

35 ---------- 

36 file_like_object : `file-like object` 

37 The file-like object containing the module code. 

38 name : `str`, optional 

39 Name to give to the module. Default: 'model'. 

40 

41 Returns 

42 ------- 

43 module : `module` 

44 The module object. 

45 """ 

46 

47 class InMemoryLoader(importlib.abc.SourceLoader): 

48 def __init__(self, data): 

49 self.data = data 

50 

51 def get_data(self, path): 

52 # In this context, 'path' is not used as data is already in memory 

53 return self.data 

54 

55 def get_filename(self, fullname): 

56 # This method is required but the filename is not important here 

57 return '<in-memory>' 

58 

59 content = file_like_object.getvalue() 

60 loader = InMemoryLoader(content) 

61 spec = importlib.util.spec_from_loader(name, loader) 

62 module = importlib.util.module_from_spec(spec) 

63 loader.exec_module(module) 

64 

65 return module 

66 

67 

68def load_module_from_file(path, name='model'): 

69 """Load a module from the specified path and return the module object. 

70 

71 Parameters 

72 ---------- 

73 path : str 

74 Path to the module file. 

75 name : str, optional 

76 Name to give to the module. Default: 'model'. 

77 

78 Returns 

79 ------- 

80 module : module 

81 The loaded module. 

82 """ 

83 spec = importlib.util.spec_from_file_location(name, path) 

84 module = importlib.util.module_from_spec(spec) 

85 spec.loader.exec_module(module) 

86 return module 

87 

88 

89def import_model_from_module(module): 

90 """Import a pytorch neural network architecture from the specified module. 

91 

92 Parameters 

93 ---------- 

94 module : module 

95 The module containing the neural network architecture. 

96 

97 Returns 

98 ------- 

99 model : `torch.nn.Module` 

100 The model class object. 

101 """ 

102 if len(module.__all__) != 1: 

103 raise ImportError(f"Multiple entries in {module}: cannot find model class.") 

104 

105 model = getattr(module, module.__all__[0]) 

106 if torch.nn.Module not in model.__bases__: 

107 raise ImportError(f"Loaded class {model}, from {module}, is not a pytorch neural network module.") 

108 

109 return model() 

110 

111 

112def import_model(path): 

113 """Import a pytorch neural network architecture from the specified path. 

114 

115 Parameters 

116 ---------- 

117 path : `str` 

118 Path to the model file. 

119 

120 Returns 

121 ------- 

122 model : `torch.nn.Module` 

123 The model class object. 

124 

125 Raises 

126 ------ 

127 ImportError 

128 Raised if a valid pytorch model cannot be found in loaded module. 

129 """ 

130 

131 module = load_module_from_file(path) 

132 return import_model_from_module(module)