python如何改字符串

字符串不可按索引赋值修改，以下是目前掌握修改字符串的方式：

原句子：I think i can make it.

要求改成：I sware i can make it.

方式1：使用replace替换

s = "i think i can make it" print(s.replace("think","swear"))

方式2：使用切片的方式进行替换，本质是拼接字符串

s = "i think i can make it" print(s[:2] + "swear" + s[7:])

方式3：使用io.StingIO，构造实例化流对象，创建子类实例，对文本进行操作。

import io s = "i think i can make it" NewS = io.StringIO(s) print(NewS.getvalue()) NewS.seek(2) NewS.write("swear") print(NewS.getvalue())

方式4：使用列表，获取字符，挨个替换，本质是拼接字符串

s = "i think i can make it" lst = list(s) # 复制成可改的列表，原s不动 print(lst) lst[2] = "s" lst[3] = "w" lst[4] = "e" lst[5] = "a" lst[6] = "r" s = "".join(lst) # 再拼回新字符串 print(s)