numpy.find_common_type¶
-
numpy.
find_common_type
(array_types, scalar_types)[source]¶ Determine common type following standard coercion rules.
Parameters: array_types : sequence
A list of dtypes or dtype convertible objects representing arrays.
scalar_types : sequence
A list of dtypes or dtype convertible objects representing scalars.
Returns: datatype : dtype
The common data type, which is the maximum of array_types ignoring scalar_types, unless the maximum of scalar_types is of a different kind (
dtype.kind
). If the kind is not understood, then None is returned.See also
Examples
>>> np.find_common_type([], [np.int64, np.float32, complex]) dtype('complex128') >>> np.find_common_type([np.int64, np.float32], []) dtype('float64')
The standard casting rules ensure that a scalar cannot up-cast an array unless the scalar is of a fundamentally different kind of data (i.e. under a different hierarchy in the data type hierarchy) then the array:
>>> np.find_common_type([np.float32], [np.int64, np.float64]) dtype('float32')
Complex is of a different type, so it up-casts the float in the array_types argument:
>>> np.find_common_type([np.float32], [complex]) dtype('complex128')
Type specifier strings are convertible to dtypes and can therefore be used instead of dtypes:
>>> np.find_common_type(['f4', 'f4', 'i4'], ['c8']) dtype('complex128')