List conversion method of numpy array

Using the method of converting list to numpy array requires specific code examples

In Python, we often need to process a large amount of numerical data, and the numpy library is the most popular one in Python One of the commonly used numerical calculation tools. It provides rich mathematical functions and convenient array operation functions. In numpy, numpy arrays are usually used to store and process data. In practical applications, we often need to convert other data structures, such as lists, into numpy arrays for subsequent numerical calculations and analysis.

Next, we will introduce several commonly used methods to convert list into numpy array.

1. Using numpy's array function

The array function in the numpy library is a commonly used function to convert other sequence data (such as list) into a numpy array. We can directly convert the list to a numpy array using the array function.

The specific code examples are as follows:

import numpy as np

my_list = [1, 2, 3, 4, 5]
my_array = np.array( my_list)

print(my_array)

The output result is:

[1 2 3 4 5]

2. Use numpy’s asarray function

In addition to using the array function, numpy also provides the asarray function to convert other sequence data into numpy arrays. The difference between the asarray function and the array function is that when the input sequence data is already a numpy array, the asarray function does not create a copy of the array, but directly returns a reference to the input data.

The specific code examples are as follows:

import numpy as np

my_list = [1, 2, 3, 4, 5]
my_array = np.asarray( my_list)

print(my_array)

The output result is the same as using the array function:

[1 2 3 4 5]

3. Using numpy The fromiter function

In addition to the above two methods, numpy also provides the fromiter function to create a numpy array by reading data one by one from the iterable object.

The specific code examples are as follows:

import numpy as np

my_list = [1, 2, 3, 4, 5]
my_array = np.fromiter( my_list, dtype=int)

print(my_array)

The output result is the same as the first two methods:

[1 2 3 4 5]

It should be noted that when using the fromiter function, we need to specify the dtype parameter to specify the data type of the numpy array.

Summary:

This article introduces three common methods to convert list into numpy array. By using the array function, asarray function or fromiter function, we can easily convert the list into a numpy array and be able to perform various numerical calculations and analysis. In actual applications, choosing the appropriate method for conversion according to needs can improve the efficiency and readability of the code.

I hope this article can help you understand the method of converting list to numpy array in numpy library. thanks for reading!

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