python中返回列表中元素的索引

 

>>> test1 = ["aaa","bbb","aaa","ccc","aaa","aaa","ddd","aaa","ccc"] >>> test1.index("aaa") ## 返回元素的首个索引 0
>>> test1.index("bbb") 1
>>> test1.index("ccc") 3
>>> test1.count("aaa") 5
>>> a = test1.count("aaa") >>> b = -1
>>> for i in range(a):  ## 返回元素的所有索引 b = test1.index("aaa",b+1,len(test1)) print("aaa:",b) aaa: 0 aaa: 2 aaa: 4 aaa: 5 aaa: 7
>>> test1 ['aaa', 'bbb', 'aaa', 'ccc', 'aaa', 'aaa', 'ddd', 'aaa', 'ccc']