python-字符串常用方法

find & index

s = 'a and b and c'
index = s.find('and') # 找不到返回-1
index = s.index('and') # 找不到报错

replace

s = s.replace('b','d')
print(s)
s = s.replace('and','or',1) # 1 代表替换次数 ；默认全部替换
print(s)