Combine Python List and Dict comprehension with counter

问题

I want to transfer a list of tuples:

[(1, 3, 5), (2, 4, 6), (7, 8, 9)]

to a list of dict (in order to create a pandas dataframe) which looks like:

[{'index':1, 'match':1},{'index':1, 'match':3},{'index':1, 'match':5},
{'index':2, 'match':2}, {'index':2, 'match':4},{'index':2, 'match':6},
{'index':3, 'match':7},{'index':3, 'match':8},{'index':3, 'match':9}]

For performance reasons I wanted to use a list and dict comprehension:

[{'index':ind, 'match': } for ind, s in enumerate(test_set, 1)]

How can this be achieved?

回答1:

You can use list comprehension use a second for to loop over the 'match'es:

[{'index':ind, 'match':match} for ind,s in enumerate(test_set,1) for match in s]

So the second for loop iterates over the elements in the tuples and for each of these elements, a dictionary is generated and added to the result.

来源：https://stackoverflow.com/questions/42486563/combine-python-list-and-dict-comprehension-with-counter