Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/numpy/_globals.py: 79%

1""" 

2Module defining global singleton classes. 

3 

4This module raises a RuntimeError if an attempt to reload it is made. In that 

5way the identities of the classes defined here are fixed and will remain so 

6even if numpy itself is reloaded. In particular, a function like the following 

7will still work correctly after numpy is reloaded:: 

8 

9 def foo(arg=np._NoValue): 

10 if arg is np._NoValue: 

11 ... 

12 

13That was not the case when the singleton classes were defined in the numpy 

14``__init__.py`` file. See gh-7844 for a discussion of the reload problem that 

15motivated this module. 

16 

17""" 

18import enum 

19 

20__ALL__ = [ 

21 'ModuleDeprecationWarning', 'VisibleDeprecationWarning', 

22 '_NoValue', '_CopyMode' 

23 ] 

24 

25 

26# Disallow reloading this module so as to preserve the identities of the 

27# classes defined here. 

28if '_is_loaded' in globals(): 

29 raise RuntimeError('Reloading numpy._globals is not allowed') 

30_is_loaded = True 

31 

32 

33class ModuleDeprecationWarning(DeprecationWarning): 

34 """Module deprecation warning. 

35 

36 The nose tester turns ordinary Deprecation warnings into test failures. 

37 That makes it hard to deprecate whole modules, because they get 

38 imported by default. So this is a special Deprecation warning that the 

39 nose tester will let pass without making tests fail. 

40 

41 """ 

42 

43 

44ModuleDeprecationWarning.__module__ = 'numpy' 

45 

46 

47class VisibleDeprecationWarning(UserWarning): 

48 """Visible deprecation warning. 

49 

50 By default, python will not show deprecation warnings, so this class 

51 can be used when a very visible warning is helpful, for example because 

52 the usage is most likely a user bug. 

53 

54 """ 

55 

56 

57VisibleDeprecationWarning.__module__ = 'numpy' 

58 

59 

60class _NoValueType: 

61 """Special keyword value. 

62 

63 The instance of this class may be used as the default value assigned to a 

64 keyword if no other obvious default (e.g., `None`) is suitable, 

65 

66 Common reasons for using this keyword are: 

67 

68 - A new keyword is added to a function, and that function forwards its 

69 inputs to another function or method which can be defined outside of 

70 NumPy. For example, ``np.std(x)`` calls ``x.std``, so when a ``keepdims`` 

71 keyword was added that could only be forwarded if the user explicitly 

72 specified ``keepdims``; downstream array libraries may not have added 

73 the same keyword, so adding ``x.std(..., keepdims=keepdims)`` 

74 unconditionally could have broken previously working code. 

75 - A keyword is being deprecated, and a deprecation warning must only be 

76 emitted when the keyword is used. 

77 

78 """ 

79 __instance = None 

80 def __new__(cls): 

81 # ensure that only one instance exists 

82 if not cls.__instance: 

83 cls.__instance = super().__new__(cls) 

84 return cls.__instance 

85 

86 def __repr__(self): 

87 return "<no value>" 

88 

89 

90_NoValue = _NoValueType() 

91 

92 

93class _CopyMode(enum.Enum): 

94 """ 

95 An enumeration for the copy modes supported 

96 by numpy.copy() and numpy.array(). The following three modes are supported, 

97 

98 - ALWAYS: This means that a deep copy of the input 

99 array will always be taken. 

100 - IF_NEEDED: This means that a deep copy of the input 

101 array will be taken only if necessary. 

102 - NEVER: This means that the deep copy will never be taken. 

103 If a copy cannot be avoided then a `ValueError` will be 

104 raised. 

105 

106 Note that the buffer-protocol could in theory do copies. NumPy currently 

107 assumes an object exporting the buffer protocol will never do this. 

108 """ 

109 

110 ALWAYS = True 

111 IF_NEEDED = False 

112 NEVER = 2 

113 

114 def __bool__(self): 

115 # For backwards compatibility 

116 if self == _CopyMode.ALWAYS: 

117 return True 

118 

119 if self == _CopyMode.IF_NEEDED: 

120 return False 

121 

122 raise ValueError(f"{self} is neither True nor False.") 

123 

124 

125_CopyMode.__module__ = 'numpy'