# What Is the Default Data Type of NumPy Data?

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Scott Campbell

Numpy is a popular library in Python used for performing numerical computations efficiently. When working with Numpy, it’s essential to understand the default data type of Numpy data. This knowledge helps in ensuring accurate calculations and avoiding unexpected results.

## The Default Data Type of Numpy Data

By default, Numpy arrays have a data type called float64, which means they store decimal numbers with double precision. The float64 data type provides a high level of precision and is suitable for most applications.

Let’s consider an example to illustrate this:

```import numpy as np

arr = np.array([1, 2, 3])
print(arr.dtype)
```

The above code creates a Numpy array `arr` with values [1, 2, 3]. By calling `arr.dtype`, we can determine the data type of the array. In this case, the output will be int64, indicating that the elements in the array are integers.

To change the default data type of a Numpy array, you can use the dtype parameter when creating an array or explicitly convert the array using the astype() function.

### Specifying Data Type during Array Creation

You can specify a different data type during array creation by passing it as an argument to the `dtype` parameter. Here’s an example:

arr = np.array([1, 2, 3], dtype=np.float32)
print(arr.dtype)

In this case, we create a Numpy array `arr` with values [1, 2, 3] and explicitly specify the data type as float32. The output will be float32, indicating that the elements in the array are now decimal numbers with single precision.

### Converting Data Type using astype()

If you already have a Numpy array and want to change its data type, you can use the astype() function.array([1, 2, 3])
arr = arr.astype(np.float16)
print(arr.dtype)

In this example, we first create a Numpy array `arr` with values [1, 2, 3]. Then, we use the `astype()` function to convert the data type to float16. The output will be float16, indicating that the elements in the array are now decimal numbers with half precision.

## List of Default Data Types in Numpy

Numpy provides various default data types to handle different types of numerical data efficiently. Here’s a list of some commonly used default data types:

• int8/int16/int32/int64: Signed integer types with different bit sizes.
• uint8/uint16/uint32/uint64: Unsigned integer types with different bit sizes.
• float16/float32/float64: Floating-point types with different levels of precision.
• complex64/complex128: Complex number types with different levels of precision.

These default data types can be used when creating Numpy arrays or converting the data type of existing arrays.

## Conclusion

In summary, the default data type of Numpy data is float64. You can specify a different data type during array creation using the `dtype` parameter or convert the data type of an existing array using the `astype()` function. Understanding the default data type and being able to modify it as needed is crucial for accurate numerical computations in Numpy.

I hope this article has provided you with a clear understanding of the default data type in Numpy and how to work with different data types in your arrays. Happy coding!