Message 293282 - Python tracker

In this PR, it will complete dictionary key with string, int, and others.

for example:

    d = {'long_key': 10, 'short_key': 20, 30: 40, (((1, 2), 3, 4), 5): 50}
    d['lo<tab>  -> d['long_key'
    d[(((1<tab> -> d[(((1, 2), 3, 4), 5)
    d[3<tab>    -> d[30

The problem is, autocomplete_w can't figure the original key is string or others, so this will be possible:

    d[long<tab> -> d[long_key]
    d[shor<tab> -> d[short_key]