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如何在numpy数组中编写case when like语句

在numpy数组中编写类似于SQL中的CASE WHEN语句,可以使用numpy的where函数来实现。

numpy的where函数可以根据给定的条件返回一个新的数组,其中满足条件的元素将被替换为指定的值,不满足条件的元素将保持不变。

下面是一个示例代码,演示如何在numpy数组中编写类似于CASE WHEN语句的功能:

代码语言:txt
复制
import numpy as np

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

# 定义条件和对应的值
conditions = [arr < 3, arr >= 3]
values = [0, 1]

# 使用numpy的where函数实现类似于CASE WHEN的功能
result = np.where(conditions[0], values[0], np.where(conditions[1], values[1], arr))

print(result)

在上面的代码中,我们首先创建了一个示例的numpy数组arr。然后,我们定义了两个条件:arr < 3和arr >= 3,并分别给出了对应的值0和1。最后,我们使用numpy的where函数根据条件和对应的值来替换数组中的元素,得到了最终的结果result。

在这个例子中,如果数组元素小于3,则替换为0;如果数组元素大于等于3,则替换为1。其他不满足条件的元素保持不变。

需要注意的是,numpy的where函数可以处理多个条件和对应的值,可以根据实际需求进行扩展和修改。

推荐的腾讯云相关产品:腾讯云服务器(CVM)和腾讯云函数(SCF)。

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