找出第三个a在字符串中的下标
str1 = 'agcadssadjkl' one=str1.index('a',) t=str1.index('a',one+1) s=str1.index('a',t+1) print(one) print(t) print(s)
'''
0
3
7
'''
str1 = 'agcadssadjkl' one=str1.index('a',) t=str1.index('a',one+1) s=str1.index('a',t+1) print(one) print(t) print(s)
'''
0
3
7
'''