How to quickly convert numpy arrays to lists

Sharing of methods to quickly convert numpy arrays into lists

In data processing and analysis, the numpy library is often used to perform fast and efficient array operations. However, sometimes we need to convert numpy arrays to lists for further processing or to interact with other types of data. Below I will share some methods to quickly convert numpy arrays to lists and provide specific code examples.

Method 1: tolist() function
The numpy array object provides a tolist() function that can quickly convert the array into a list. This function returns a list of array elements.

The following is a sample code using the tolist() function:

import numpy as np

# 创建一个numpy数组
arr = np.array([1, 2, 3, 4, 5])

# 将numpy数组转换为列表
arr_list = arr.tolist()

print(arr_list)

Running result:

[1, 2, 3, 4, 5]

Method 2: tolist() function and multi-dimensional array
If we To process multi-dimensional numpy arrays and convert them into lists, we can apply the tolist() function on each dimension of the array, i.e. call the tolist() function multiple times.

The following is a sample code that uses the tolist() function to process multi-dimensional arrays:

import numpy as np

# 创建一个二维numpy数组
arr = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

# 将numpy数组转换为列表
arr_list = arr.tolist()

print(arr_list)

Running results:

[[1, 2, 3], [4, 5, 6], [7, 8, 9]]

Method 3: Use list comprehensions
In addition to tolist () function, we can also use list comprehensions to quickly convert numpy arrays into lists. List comprehensions can be used to process and convert array elements very concisely.

The following is a sample code using list comprehension:

import numpy as np

# 创建一个numpy数组
arr = np.array([1, 2, 3, 4, 5])

# 使用列表推导式将数组转换为列表
arr_list = [x for x in arr]

print(arr_list)

Running result:

[1, 2, 3, 4, 5]

Method 4: Use np.ndarray.tolist() function
Except tolist() function, the numpy library also provides an np.ndarray.tolist() function, which can also quickly convert numpy arrays into lists. Different from the tolist() function in method 1, this function is called through the function provided by the numpy library.

The following is a sample code using the np.ndarray.tolist() function:

import numpy as np

# 创建一个numpy数组
arr = np.array([1, 2, 3, 4, 5])

# 使用np.ndarray.tolist()函数将数组转换为列表
arr_list = np.ndarray.tolist(arr)

print(arr_list)

Running results:

[1, 2, 3, 4, 5]

Summary:

This article introduces Four methods to quickly convert numpy arrays into lists: tolist() function, tolist() function and multidimensional arrays, using list comprehensions, and using np.ndarray.tolist() function. Different methods are suitable for different scenarios, and readers can choose the appropriate method to convert numpy arrays into lists according to specific needs. At the same time, this article also provides corresponding code examples. Readers can run the code directly to understand the use and effect of each method. I hope this article can provide some help to readers in converting numpy arrays and lists.

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