NumPy Data Type and Conversion

Data type - dtype in NumPy is different from the primitive data types in Python, for example, dtype has the type with higher resolution that is useful in the data calculation.

NumPy Data Type

When creating a new ndarray data, you can define the data type of the element by string or or data type constants in the numpy library.

import numpy as np

# by string
test = np.array([4, 5, 6], dtype='int64')

# by data type constant in numpy
test = np.array([7, 8, 8], dtype=np.int64)

Data Type Conversion

After the data instance is created, you can change the type of the element to another type with astype() method, such as from integer to floating and so on.

>>> import numpy as np
>>> test = np.array([11, 12, 13, 14], dtype="int32")
>>> x = test.astype('float32')
>>> x
array([11., 12., 13., 14.], dtype=float32)
>>> test, test.dtype
(array([11, 12, 13, 14]), dtype('int32'))