Question

Let’s say we have the following data

all_values = (('a', 0, 0.1), ('b', 1, 0.5), ('c', 2, 1.0))

from which we want to produce a list of dictionaries like so:

[{'location': 0, 'name': 'a', 'value': 0.1},
 {'location': 1, 'name': 'b', 'value': 0.5},
 {'location': 2, 'name': 'c', 'value': 1.0}]

What’s the most elegant way to do this in Python?

The best solution I’ve been able to come up with is

>>> import itertools
>>> zipped = zip(itertools.repeat(('name', 'location', 'value')), all_values)
>>> zipped
[(('name', 'location', 'value'), ('a', 0, 0.1)),
 (('name', 'location', 'value'), ('b', 1, 0.5)),
 (('name', 'location', 'value'), ('c', 2, 1.0))]
>>> dicts = [dict(zip(*e)) for e in zipped]
>>> dicts
[{'location': 0, 'name': 'a', 'value': 0.1},
 {'location': 1, 'name': 'b', 'value': 0.5},
 {'location': 2, 'name': 'c', 'value': 1.0}]

It seems like a more elegant way to do this exists, probably using more of the tools in itertools.

Answer 1

How about:

In [8]: [{'location':l, 'name':n, 'value':v} for (n, l, v) in all_values]
Out[8]: 
[{'location': 0, 'name': 'a', 'value': 0.1},
 {'location': 1, 'name': 'b', 'value': 0.5},
 {'location': 2, 'name': 'c', 'value': 1.0}]

or, if you prefer a more general solution:

In [12]: keys = ('name', 'location', 'value')

In [13]: [dict(zip(keys, values)) for values in all_values]
Out[13]: 
[{'location': 0, 'name': 'a', 'value': 0.1},
 {'location': 1, 'name': 'b', 'value': 0.5},
 {'location': 2, 'name': 'c', 'value': 1.0}]