python打印列表中指定元素的所有下标

1》法一： song@ubuntu:~$ vi find2.py song@ubuntu:~$ more find2.py l=[1,2,3,4,7,2,5,6,2,8,9,0] first=0 for i in range(l.count(2)):     new_l=l[first:]     index=first+new_l.index(2)     print 'find the index of 2:',index     first=index+1 song@ubuntu:~$ python find2.py find the index of 2: 1 find the index of 2: 5 find the index of 2: 8 song@ubuntu:~$  2》法二： song@ubuntu:~$ vi find_2.py song@ubuntu:~$ more find_2.py l=[2,2,3,4,5,1,2,3,1,2,3,4,5] first=True for i in range(l.count(2)):     if first==True:         pos=l.index(2)         first=False     else:         pos=l.index(2,pos+1)

    print pos

song@ubuntu:~$ python find_2.py 0 1 6 9 song@ubuntu:~$ 3》法三： song@ubuntu:~$ vi find_2_1.py song@ubuntu:~$ more find_2_1.py l=[2,2,3,4,5,1,2,3,1,2,3,4,5] for i in range(len(l)):     if l[i]==2:

        print i

song@ubuntu:~$ python find_2_1.py 0 1 6 9

song@ubuntu:~$ 

4》法四：

song@ubuntu:~$ vi find_2.py song@ubuntu:~$ more find_2.py l=[2,2,3,4,5,1,2,3,1,2,3,4,5] for i in range(l.count(2)):     if i==0:         pos=l.index(2)     else:         pos=l.index(2,pos+1)     print pos song@ubuntu:~$ python find_2.py 0 1 6 9

5》法五：

song@ubuntu:~$ vi find_2.py song@ubuntu:~$ more find_2.py l=[2,2,3,4,5,1,2,3,1,2,3,4,5] pos=-1 for i in range(l.count(2)):     pos=l.index(2,pos+1)     print pos song@ubuntu:~$ python find_2.py 0 1 6 9

（完）