'''集合的生成式'''
s='hello,hello'
print(s.index('lo')) #3
print(s.find('lo')) #3
print(s.rindex('lo')) #9
print(s.rfind('lo')) #9
'''如果查找不存在的元素'''
#print(s.index('k')) #ValueError: substring not found 抛异常
print(s.find('k')) #-1 不会抛异常返回值为-1
#print(s.rindex('k')) #ValueError: substring not found 抛异常
print(s.rfind('k')) #-1 不会抛异常返回值为-1
E:\PycharmProjects\pythonProject\venv\Scripts\python.exe E:/PycharmProjects/pythonProject/demon1/demo14.py 3 3 9 9 -1 -1
标签：#-,lo,substring,print,字符串,操作,异常,9.2 From： https://www.cnblogs.com/988MQ/p/16653635.html