字串字面值
1. "abc" # ascii in python 2.7.x, unicode python 3.x
2. u"中文" # unicode 編碼
3. b"abc" # ascii in python 2.7.x, bytes in python 3.x
4. u"\u1234" # unicode 編碼
內建字串運算
s = “123”
1. s[0] == "1" # 索引運算
2. s[-1] == "3" # 負索引
3. s[1:3] == "23" # 切片
4. s[0:3] == "123" # 切片
5. s[:3] == s[0:3] # True
6. s[:-1] == s[0:2] # True
7. s[:] == "abc" # 拷貝
8. s + "456" == "123456" # 串接
9. s * 3 == "123123123" # 重複
字串不可變性
python的字串不可變
也就是不存在這種用法 s[0] = “a”
使用串接替代 s = “a” + s[1:]