Question

考虑如下列表：

entry = [＆＃39; document1＆＃39;，＆＃39; document2＆＃39;，＆＃39; document1＆＃39;，＆＃39; document2＆＃39; ]

现在，如果我运行以下代码：

for i in entry:
   print i + "has index" + entry.index(i)

它将输出显示为

document1 has index 0
document2 has index 1
document1 has index 0
document2 has index 1

但输出应该是：

document1 has index 0
document2 has index 1
document1 has index 2
document2 has index 3

任何人都可以帮助我在这段代码中编辑什么？

PS：我想使用一个函数，而不是引入一个随列表一起递增的虚拟变量。

Answer 1

您可以编写自己的函数（使用枚举）并在代码中使用它 - 然后您的代码不会被无关的注册混乱：

from collections import defaultdict
def element_indices(entry):
    result = defaultdict(list)
    for ndx, element in enumerate(entry):
        result[element].append(ndx)
    return result

用法：

entry = [ 'document1', 'document2', 'document1', 'document2' ]
for element, indices in element_indices(entry).items():
    print '{} is found at indices {}'.format(element, indices)

# >>> 
# document1 is found at indices [0, 2]
# document2 is found at indices [1, 3]
# >>>

Python在列表中查找重复元素的索引

1 个答案: