在某个索引处放置特定字符串

Question

我想在某个索引处放置字符串。假设我们从一个空字符串x=""开始。然后我想把字母a，e，I，o和u放在索引0，2，4，6，8处，这样就得到x="a e i o u"。然后，也许我想在索引1，3，5处加z，y，x，得到x=azeyixo u。我该怎么做？你知道吗

Answer 1

def join_str(tmp_dict, x):
    lst_x = list(x)
    lst_keys = list(tmp_dict.keys())
    lst_keys = [int(key) for key in lst_keys]
    max_key = max(lst_keys)
    for i in range(len(lst_x), max_key + 1):
        lst_x.append(' ')
    for key in tmp_dict:
        lst_x[key] = tmp_dict[key]
    return ''.join(lst_x)

这应该做你的工作，虽然它可以优化和输入应该是一个dict，其中键是你想要插入元素的索引，值应该是实际值。你知道吗

Answer 2

你可以做一个字符串生成器。开始吧。你知道吗

>>> class MutableString:
...     def __init__(self, s):
...         self._string = s
...         
...     def __setitem__(self, index, s):
...         if index < len(self._string):
...             self._string = self._string[:index] + s + self._string[index+len(s):]
...         else:
...             self._string = self._string + ' ' * (index -len(self._string)) + s
...         
...     def __str__(self):
...         return self._string
...              
>>> ms = MutableString("hello world!")
>>> print ms
hello world!
>>> ms[6] = "people"
>>> print ms
hello people
>>> ms = MutableString('')
>>> ms[0] = 'a'; ms[2] = 'e'; ms[4] = 'i'; ms[6] = 'o'; ms[8] = 'u'
>>> print ms
a e i o u
>>> ms[1] = 'z'; ms[3] = 'y'; ms[5] = 'x'
>>> print ms
azeyixo u

Answer 3

def str_index(s, ilist, clist):
    for i, c  in zip(ilist,clist):
        if i < len(s):
            s = s[:i] + c + s[i+1:]
        else:
            s = s + " " * (i - len(s)) + c
    return s

if __name__ == '__main__':
    x = str_index("", [0,2,4,6,8], ['a','e','i','o','u'])
    x = str_index(x, [1,3,5], ['x','y','z'])
    print(x)