python字符串运算

1.加法：

s1 = "hap"

s2 = "py"

s = s1+s2

print(s)

----->happy

2.乘法

s1 = "happy"

s = s1*3

print(s)

------>happyhappyhappy

3.字符串可用单引号、双引号、三引号