列表中的Python索引更改

Question

# write a function that accepts a list and the indexes of two elements in the list,
# and swaps that two elements of the list, and return the swapped list. 
# for example, if the arguments of the function are [23,65,19,90]m index1 = 1, and index2 = 3,
# then it will return [23,90,19,65].


# Swap function

def swapLst(newLst):
    size = len(newLst)
     
    # Swapping
    temp = newLst[0]
    newLst[0] = newLst[size - 1]
    newLst[size - 1] = temp
     
    return newLst
     
newLst = [23,65,19,90]
print(swapLst(newLst))

您好，我的问题：如何更改代码以更改列表中的任何索引。我的程序只会更改和最后一个索引，我需要帮助。谢谢你！

Answer 1

您可以使用a，b = b，a在python中交换变量，因此您可以将列表元素与其索引交换：

a = [1, 2, 3, 1, 2, 3, 5] 

def swap(l, i, j):
    l[i], l[j] = l[j], l[i]
    return l
print(swap(a, 0, 1))

输出：

[2, 1, 3, 1, 2, 3, 5]

Answer 2

为了这样做，您也需要接受其他整数作为参数。
a，b = b，a
更容易交换
代码：

def swapLst(newlst, in1, in2): 
    newlst[in1], newlst[in2] = newlst[in2], newlst[in1]
    return newlst
 
newLst = [23,65,19,90] 
print(swapLst(newLst, 1, 3))

输出：

[23, 90, 19, 65]

Answer 3

您可以修改swaplst函数以在任何给定的索引上交换元素：

def swapLst(lst, index1, index2):
    # Check if indices are valid
    if index1 >= len(lst) or index2 >= len(lst):
        print("Invalid index")
        return lst
    
    # Swapping
    temp = lst[index1]
    lst[index1] = lst[index2]
    lst[index2] = temp
     
    return lst

# Example usage
lst = [23,65,19,90]
new_lst = swapLst(lst, 1, 3)
print(new_lst)   # Output: [23, 90, 19, 65]