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diff --git a/numpy/exceptions.py b/numpy/exceptions.py new file mode 100644 index 000000000..2f8438101 --- /dev/null +++ b/numpy/exceptions.py @@ -0,0 +1,231 @@ +""" +Exceptions and Warnings (:mod:`numpy.exceptions`) +================================================= + +General exceptions used by NumPy. Note that some exceptions may be module +specific, such as linear algebra errors. + +.. versionadded:: NumPy 1.25 + + The exceptions module is new in NumPy 1.25. Older exceptions remain + available through the main NumPy namespace for compatibility. + +.. currentmodule:: numpy.exceptions + +Warnings +-------- +.. autosummary:: + :toctree: generated/ + + ComplexWarning Given when converting complex to real. + VisibleDeprecationWarning Same as a DeprecationWarning, but more visible. + +Exceptions +---------- +.. autosummary:: + :toctree: generated/ + + AxisError Given when an axis was invalid. + DTypePromotionError Given when no common dtype could be found. + TooHardError Error specific to `numpy.shares_memory`. + +""" + + +__all__ = [ + "ComplexWarning", "VisibleDeprecationWarning", "ModuleDeprecationWarning", + "TooHardError", "AxisError", "DTypePromotionError"] + + +# Disallow reloading this module so as to preserve the identities of the +# classes defined here. +if '_is_loaded' in globals(): + raise RuntimeError('Reloading numpy._globals is not allowed') +_is_loaded = True + + +class ComplexWarning(RuntimeWarning): + """ + The warning raised when casting a complex dtype to a real dtype. + + As implemented, casting a complex number to a real discards its imaginary + part, but this behavior may not be what the user actually wants. + + """ + pass + + +class ModuleDeprecationWarning(DeprecationWarning): + """Module deprecation warning. + + .. warning:: + + This warning should not be used, since nose testing is not relevant + anymore. + + The nose tester turns ordinary Deprecation warnings into test failures. + That makes it hard to deprecate whole modules, because they get + imported by default. So this is a special Deprecation warning that the + nose tester will let pass without making tests fail. + + """ + + +class VisibleDeprecationWarning(UserWarning): + """Visible deprecation warning. + + By default, python will not show deprecation warnings, so this class + can be used when a very visible warning is helpful, for example because + the usage is most likely a user bug. + + """ + + +# Exception used in shares_memory() +class TooHardError(RuntimeError): + """max_work was exceeded. + + This is raised whenever the maximum number of candidate solutions + to consider specified by the ``max_work`` parameter is exceeded. + Assigning a finite number to max_work may have caused the operation + to fail. + + """ + + pass + + +class AxisError(ValueError, IndexError): + """Axis supplied was invalid. + + This is raised whenever an ``axis`` parameter is specified that is larger + than the number of array dimensions. + For compatibility with code written against older numpy versions, which + raised a mixture of `ValueError` and `IndexError` for this situation, this + exception subclasses both to ensure that ``except ValueError`` and + ``except IndexError`` statements continue to catch `AxisError`. + + .. versionadded:: 1.13 + + Parameters + ---------- + axis : int or str + The out of bounds axis or a custom exception message. + If an axis is provided, then `ndim` should be specified as well. + ndim : int, optional + The number of array dimensions. + msg_prefix : str, optional + A prefix for the exception message. + + Attributes + ---------- + axis : int, optional + The out of bounds axis or ``None`` if a custom exception + message was provided. This should be the axis as passed by + the user, before any normalization to resolve negative indices. + + .. versionadded:: 1.22 + ndim : int, optional + The number of array dimensions or ``None`` if a custom exception + message was provided. + + .. versionadded:: 1.22 + + + Examples + -------- + >>> array_1d = np.arange(10) + >>> np.cumsum(array_1d, axis=1) + Traceback (most recent call last): + ... + numpy.exceptions.AxisError: axis 1 is out of bounds for array of dimension 1 + + Negative axes are preserved: + + >>> np.cumsum(array_1d, axis=-2) + Traceback (most recent call last): + ... + numpy.exceptions.AxisError: axis -2 is out of bounds for array of dimension 1 + + The class constructor generally takes the axis and arrays' + dimensionality as arguments: + + >>> print(np.AxisError(2, 1, msg_prefix='error')) + error: axis 2 is out of bounds for array of dimension 1 + + Alternatively, a custom exception message can be passed: + + >>> print(np.AxisError('Custom error message')) + Custom error message + + """ + + __slots__ = ("axis", "ndim", "_msg") + + def __init__(self, axis, ndim=None, msg_prefix=None): + if ndim is msg_prefix is None: + # single-argument form: directly set the error message + self._msg = axis + self.axis = None + self.ndim = None + else: + self._msg = msg_prefix + self.axis = axis + self.ndim = ndim + + def __str__(self): + axis = self.axis + ndim = self.ndim + + if axis is ndim is None: + return self._msg + else: + msg = f"axis {axis} is out of bounds for array of dimension {ndim}" + if self._msg is not None: + msg = f"{self._msg}: {msg}" + return msg + + +class DTypePromotionError(TypeError): + """Multiple DTypes could not be converted to a common one. + + This exception derives from ``TypeError`` and is raised whenever dtypes + cannot be converted to a single common one. This can be because they + are of a different category/class or incompatible instances of the same + one (see Examples). + + Notes + ----- + Many functions will use promotion to find the correct result and + implementation. For these functions the error will typically be chained + with a more specific error indicating that no implementation was found + for the input dtypes. + + Typically promotion should be considered "invalid" between the dtypes of + two arrays when `arr1 == arr2` can safely return all ``False`` because the + dtypes are fundamentally different. + + Examples + -------- + Datetimes and complex numbers are incompatible classes and cannot be + promoted: + + >>> np.result_type(np.dtype("M8[s]"), np.complex128) + DTypePromotionError: The DType <class 'numpy.dtype[datetime64]'> could not + be promoted by <class 'numpy.dtype[complex128]'>. This means that no common + DType exists for the given inputs. For example they cannot be stored in a + single array unless the dtype is `object`. The full list of DTypes is: + (<class 'numpy.dtype[datetime64]'>, <class 'numpy.dtype[complex128]'>) + + For example for structured dtypes, the structure can mismatch and the + same ``DTypePromotionError`` is given when two structured dtypes with + a mismatch in their number of fields is given: + + >>> dtype1 = np.dtype([("field1", np.float64), ("field2", np.int64)]) + >>> dtype2 = np.dtype([("field1", np.float64)]) + >>> np.promote_types(dtype1, dtype2) + DTypePromotionError: field names `('field1', 'field2')` and `('field1',)` + mismatch. + + """ + pass |