Question

我想在这里将列表复制到新列表中，但我的代码无效：

l = list(range(0,101,2))
n = []

def change(l):
    for i in range (len(l)):
        k = l.copy()
        n[k] = l[:] 


print (l)
print (n)

我想将l列表复制到n列表中，但是不起作用。预先感谢您的帮助。

Answer 1

>>>l = range(0,101,2)
>>>n = [x for x in l]

Answer 2

您可以使用https://docs.python.org/2/library/copy.html

import copy
n = copy.copy(l)

为避免n = l出现以下问题：

l = list(range(0,21,2))
n = []
n = l
l.append(1000)
print (n) #=> [0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 1000]

Answer 3

n = l[:]是不使用任何模块复制列表的一种方法：

l = list(range(0,101,2)) # get list of even values from 0 to 100
n = l[:]                 # copy data from l to n
print (l)                # check data of l
print(n)                 # check data of n
l.pop()                  # remove last element from l
print(l)                 # It prints only 0 to 98
print(n)                 # It prints from 0 to 100 (can you see here, changing l doesnot impact n)

现在，如果直接使用n = l，则l中的任何更改都会更改n中的值，请检查以下代码：

l = list(range(0,101,2))

n=l
print (l)                # check data of l
print(n)                 # check data of n
l.pop()                  # remove last element from l
print(l)                 # It prints from 0 to 98
print(n)                 # It prints from 0 to 98

Python将列表复制到新列表？

3 个答案: