NumPy数组传递值 [英] Numpy array pass-by-value

问题描述

我有一个由函数更改的numpy数组. 调用函数后，我要继续使用数组的初始值(调用修改函数之前的值)

I have a numpy array that is changed by a function. After calling the function I want to proceed with the initial value of the array (value before calling the modifying function)

# Init of the array
array = np.array([1, 2, 3])

# Function that modifies array
func(array)

# Print the init value [1,2,3]
print(array)

是否可以通过值传递数组，或者我有义务进行深层复制?

Is there a way to pass the array by value or am I obligated to make a deep copy?

推荐答案

正如我提到的，np.ndarray对象是可变数据结构.这意味着在对对象进行更改时，任何引用特定对象的变量都将反映更改.

As I mentioned, np.ndarray objects are mutable data structures. This means that any variables that refer to a particular object will all reflect changes when a change is made to the object.

但是，请记住，最个用于转换数组的numpy函数会返回新的数组对象，而原始数组则保持不变.

However, keep in mind that most numpy functions that transform arrays return new array objects, leaving the original unchanged.

在这种情况下，您需要执行的操作取决于您正在执行的操作.如果您的函数在适当的地方修改了相同的数组，那么您需要将副本传递给该函数.您可以使用 np.ndarray.copy .

What you need to do in this scenario depends on exactly what you're doing. If your function modifies the same array in place, then you'll need to pass a copy to the function. You can do this with np.ndarray.copy.

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