python - python：带有列表索引的字典理解

Question

我想使用包含列表中值的索引位置的键创建字典。我正在使用python 2.7。考虑我的尝试：

LL = ["this","is","a","sample","list"]
LL_lookup = {LL.index(l):l for (LL.index(l), l) in LL}

# desired output
print LL_lookup[1]
>> is

我认识到在此示例中不需要字典 -LL[1]会产生相同的结果。尽管如此，我们可以想象这样一种情况：1）给定一个更复杂的例子，字典更可取，b）字典查找可能会通过大量迭代产生边际性能增益。

Answer 1

>>> LL = ["this","is","a","sample","list"]
>>> dict(enumerate(LL))
{0: 'this', 1: 'is', 2: 'a', 3: 'sample', 4: 'list'}

Answer 2

inp = ["this","is","a","sample","list"]

print {idx: value for idx, value in enumerate(inp)}