替换列表列表中的值

# 方法1：直接修改列表元素
def replace_list_elements_1(lst, old_value, new_value):
    for i in range(len(lst)):
        if lst[i] == old_value:
            lst[i] = new_value

# 方法2：使用列表推导式
def replace_list_elements_2(lst, old_value, new_value):
    new_lst = [new_value if x == old_value else x for x in lst]
    return new_lst

# 方法3：使用列表的内置替换函数
def replace_list_elements_3(lst, old_value, new_value):
    lst = [new_value if x == old_value else x for x in lst]
    return lst

# 示例用法
my_list = [1, 2, 3, 4, 5, 3, 6]
old_value = 3
new_value = 9

replace_list_elements_1(my_list, old_value, new_value)
print(my_list)  # 输出: [1, 2, 9, 4, 5, 9, 6]

new_list = replace_list_elements_2(my_list, old_value, new_value)
print(new_list)  # 输出: [1, 2, 9, 4, 5, 9, 6]

new_list = replace_list_elements_3(my_list, old_value, new_value)
print(new_list)  # 输出: [1, 2, 9, 4, 5, 9, 6]