使用列表元素作为索引将列表转换为字典-Python

Question

From Python: create dict from list and auto-gen/increment the keys (list is the actual key values)? , it's possible to create a dict from a list using enumerate to generate tuples made up of incremental keys and elements in life, ie:

>>> x = ['a', 'b', 'c']
>>> list(enumerate(x))
[(0, 'a'), (1, 'b'), (2, 'c')]
>>> dict(enumerate(x))
{0: 'a', 1: 'b', 2: 'c'}

It is also possible to reverse the key-value by iterating through every key in the dict (assuming that there is a one-to-one mapping between key-value pairs:

>>> x = ['a', 'b', 'c']
>>> d = dict(enumerate(x))
>>> {v:k for k,v in d.items()}
{'a': 0, 'c': 2, 'b': 1}

Given the input list ['a', 'b', 'c'] , how can achieve the dictionary where the elements as the key and incremental index as values without trying to loop an additional time to reverse the dictionary ?

Answer 1

How about simply:

>>> x = ['a', 'b', 'c']
>>> {j:i for i,j in enumerate(x)}
{'a': 0, 'c': 2, 'b': 1}