一、字符串方法索引
say = “there are %d monkeys in the %s!”,%d表示整数,%s表示字符串字符串
say %(3,'tree')方法
print(say %(3,'tree'))字符
二、索引
hw = "hello world"
hw[0]
hw.find('world')结果为6,此时反查hw[6:]结果为world