| | """ |
| | Module defining global singleton classes. |
| | |
| | This module raises a RuntimeError if an attempt to reload it is made. In that |
| | way the identities of the classes defined here are fixed and will remain so |
| | even if numpy itself is reloaded. In particular, a function like the following |
| | will still work correctly after numpy is reloaded:: |
| | |
| | def foo(arg=np._NoValue): |
| | if arg is np._NoValue: |
| | ... |
| | |
| | That was not the case when the singleton classes were defined in the numpy |
| | ``__init__.py`` file. See gh-7844 for a discussion of the reload problem that |
| | motivated this module. |
| | |
| | """ |
| | import enum |
| |
|
| | from ._utils import set_module as _set_module |
| |
|
| | __all__ = ['_NoValue', '_CopyMode'] |
| |
|
| |
|
| | |
| | |
| | if '_is_loaded' in globals(): |
| | raise RuntimeError('Reloading numpy._globals is not allowed') |
| | _is_loaded = True |
| |
|
| |
|
| | class _NoValueType: |
| | """Special keyword value. |
| | |
| | The instance of this class may be used as the default value assigned to a |
| | keyword if no other obvious default (e.g., `None`) is suitable, |
| | |
| | Common reasons for using this keyword are: |
| | |
| | - A new keyword is added to a function, and that function forwards its |
| | inputs to another function or method which can be defined outside of |
| | NumPy. For example, ``np.std(x)`` calls ``x.std``, so when a ``keepdims`` |
| | keyword was added that could only be forwarded if the user explicitly |
| | specified ``keepdims``; downstream array libraries may not have added |
| | the same keyword, so adding ``x.std(..., keepdims=keepdims)`` |
| | unconditionally could have broken previously working code. |
| | - A keyword is being deprecated, and a deprecation warning must only be |
| | emitted when the keyword is used. |
| | |
| | """ |
| | __instance = None |
| | def __new__(cls): |
| | |
| | if not cls.__instance: |
| | cls.__instance = super().__new__(cls) |
| | return cls.__instance |
| |
|
| | def __repr__(self): |
| | return "<no value>" |
| |
|
| |
|
| | _NoValue = _NoValueType() |
| |
|
| |
|
| | @_set_module("numpy") |
| | class _CopyMode(enum.Enum): |
| | """ |
| | An enumeration for the copy modes supported |
| | by numpy.copy() and numpy.array(). The following three modes are supported, |
| | |
| | - ALWAYS: This means that a deep copy of the input |
| | array will always be taken. |
| | - IF_NEEDED: This means that a deep copy of the input |
| | array will be taken only if necessary. |
| | - NEVER: This means that the deep copy will never be taken. |
| | If a copy cannot be avoided then a `ValueError` will be |
| | raised. |
| | |
| | Note that the buffer-protocol could in theory do copies. NumPy currently |
| | assumes an object exporting the buffer protocol will never do this. |
| | """ |
| |
|
| | ALWAYS = True |
| | NEVER = False |
| | IF_NEEDED = 2 |
| |
|
| | def __bool__(self): |
| | |
| | if self == _CopyMode.ALWAYS: |
| | return True |
| |
|
| | if self == _CopyMode.NEVER: |
| | return False |
| |
|
| | raise ValueError(f"{self} is neither True nor False.") |
| |
|