Question

我想创建一个在数组中每个字符串前面添加特定单词的函数。最后我想改变数组。我有这段代码：

def make_great(magicians):
    """Change magicians"""
    for magician in magicians:
        magician = "the Great" + magician


magicians = ["hudini", "angel", "teller", "anderson", "copperfield"]
make_great(magicians)
print(magicians)

此代码不会更改数组。我怎样才能使我的功能发挥作用？

Answer 1

您可以使用enumerate使用索引和值循环遍历列表，然后使用索引将值直接更改为列表：

def make_great(magicians):
    for index, magician in enumerate(magicians):
        magicians[index] = "the Great " + magician

Answer 2

在这种情况下，

enumerate是最好的事情，然后修改数组中每个索引的值。

for i, magician in enumerate(magicians):
    magicians[i] = "the Great " + magician

Answer 3

当你使用for-each循环时：

def make_great(magicians):    
    for magician in magicians:
        magician = "The Great" + magician

你实际上正在创造一个新的魔术师;所以修改它不会像你找到的那样修改原始数组。

相反，迭代数组中的项目：

def make_great(magicians):    
    for i in range(len(magicians)):
        magicians[i] = "The Great" + magicians[i]

或使用上面提出的枚举器。请参阅：How to modify list entries during for loop?

Answer 4

您可以使用结合magic和lambda together

的小型map来完成此操作

>>> magicians = ['hudini', 'angel', 'teller', 'anderson', 'copperfield']
>>> map(lambda el:'pre_'+el,magicians)
['pre_hudini', 'pre_angel', 'pre_teller', 'pre_anderson', 'pre_copperfield']

尝试here

如何修改数组中的字符串？

4 个答案: