Beppe wrote:
> Il giorno domenica 18 ottobre 2015 13:00:44 UTC+2, Peter Otten ha scritto:
>> Beppe wrote:
>>
>> > hi to everybody, I must turn a tuple of lists into a dictionary.
>> >
>> > something like
>> >
>> > (['a', 'b', 'c', 'd', 'e', 'f'], ['g', 'h', 'i'], ['l', 'm', 'n', 'o'])
>> >
>> > note that the length af each list is variable
>> >
>> > must return
>> >
>> > a ['b', 'c', 'd', 'e', 'f']
>> > b ['a', 'c', 'd', 'e', 'f']
>> > c ['a', 'b', 'd', 'e', 'f']
>> > d ['a', 'b', 'c', 'e', 'f']
>> > e ['a', 'b', 'c', 'd', 'f']
>> > f ['a', 'b', 'c', 'd', 'e']
>> > g ['h', 'i']
>> > h ['g', 'i']
>> > i ['g', 'h']
>> > l ['m', 'n', 'o']
>> > m ['l', 'n', 'o']
>> > n ['l', 'm', 'o']
>> > o ['l', 'm', 'n']
>>
>> What do you want to do with items that occur in more than one list?
>>
>> If there are no such duplicate items it's easy:
>>
>> >>> lists = (['a', 'b', 'c', 'd', 'e', 'f'], ['g', 'h', 'i'], ['l', 'm',
>> 'n', 'o'])
>> >>> d = {
>> ... c: items[:i] + items[i+1:]
>> ... for items in lists
>> ... for i, c in enumerate(items)
>> ... }
>> >>> pprint.pprint(d)
>> {'a': ['b', 'c', 'd', 'e', 'f'],
>> 'b': ['a', 'c', 'd', 'e', 'f'],
>> 'c': ['a', 'b', 'd', 'e', 'f'],
>> 'd': ['a', 'b', 'c', 'e', 'f'],
>> 'e': ['a', 'b', 'c', 'd', 'f'],
>> 'f': ['a', 'b', 'c', 'd', 'e'],
>> 'g': ['h', 'i'],
>> 'h': ['g', 'i'],
>> 'i': ['g', 'h'],
>> 'l': ['m', 'n', 'o'],
>> 'm': ['l', 'n', 'o'],
>> 'n': ['l', 'm', 'o'],
>> 'o': ['l', 'm', 'n']}
>
> hi Peter, you are right, no duplicates are admitted between lists,
> anyway your solution,works on python 3 but not on 2.
> however beautiful list comprehension solution.
> I will try to suit it for the python version i need
The above code will work without changes in Python 2.7. For older Python
versions you can replace the dict comprehension with a generator expression:
>>> d = dict(
... (c, items[:i] + items[i+1:])
... for items in lists
... for i, c in enumerate(items)
... )
>>> pprint.pprint(d)
{'a': ['b', 'c', 'd', 'e', 'f'],
'b': ['a', 'c', 'd', 'e', 'f'],
'c': ['a', 'b', 'd', 'e', 'f'],
'd': ['a', 'b', 'c', 'e', 'f'],
'e': ['a', 'b', 'c', 'd', 'f'],
'f': ['a', 'b', 'c', 'd', 'e'],
'g': ['h', 'i'],
'h': ['g', 'i'],
'i': ['g', 'h'],
'l': ['m', 'n', 'o'],
'm': ['l', 'n', 'o'],
'n': ['l', 'm', 'o'],
'o': ['l', 'm', 'n']}
I have no Python below 2.7 ready to test, but this version should work for
Python 2.4 and above. If you find explict loops easier to understand:
>>> d = {}
>>> for items in lists:
... for i, c in enumerate(items):
... assert c not in d
... d[c] = items[:i] + items[i+1:]
...
should work for Python 2.3 and above (untested). I have smuggled in an
assertion that checks for duplicate keys.
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