将元组与多个项目python合并

Question

I need my script to merge tuples with multiple items. I have:

list = [('France', 'Euro', 'Paris'), ('France', 'Euro', 'Marseille'), 
('Allemagne', 'Euro', 'Berlin'),
('Allemagne', 'Euro', 'Hambourg'), ('Allemagne', 'Euro', 'Munich'),
('France', 'Euro', 'Lyon'), ('Turquie', 'Livre', 'Ankara')]

and I want:

list = [('France', 'Euro', 'Paris', 'Marseille', 'Lyon'), 
('Allemagne', 'Euro', 'Berlin', 'Hambourg', 'Munich'),
('Turquie', 'Livre', 'Ankara')]

I have found :

for t in j:
    d.setdefault(t[0], set()).add(t[1])
result = tuple(tuple([k]+list(v)) for k, v in d.items())

But I can only merge item if I have 2 item per line.

I have tried to modify the logic but have not succeeded.

Answer 1

There are multiple problems with your code:

1. You are looking to group by Country and Currency. Yet your dictionary only uses Country keys.
2. Your tuple comprehension will only ever return a tuple, while you want a list of tuples as output.
3. You are shadowing the built-in list class, you should never do this.

You can instead use collections.defaultdict with tuple keys, followed by a list comprehension:

from collections import defaultdict

d = defaultdict(list)

for ctry, ccy, city in L:
    d[(ctry, ccy)].append(city)

res = [k+tuple(v) for k, v in d.items()]

print(res)

[('France', 'Euro', 'Paris', 'Marseille', 'Lyon'),
 ('Allemagne', 'Euro', 'Berlin', 'Hambourg', 'Munich'),
 ('Turquie', 'Livre', 'Ankara')]

Answer 2

It seems to me that you want to iterate through the list, and combine the third element (being the currency) of each tuple which contains the same second and first element

This is how I would proceed:

currencies = {}
for i in lists:
    if (i[0],i[1]) in currencies.keys():
        currencies[(i[0],i[1])] = currencies[(i[0],i[1])]|set([i[2]])
    else:
        currencies[(i[0],i[1])] = set([i[2]])
lists = []
for c in currencies:
    lists.append(list(c) + list(currencies[c]))
print(lists)

this will yield: [['France', 'Euro', 'Marseille', 'Lyon', 'Paris'], ['Allemagne', 'Euro', 'Berlin', 'Munich', 'Hambourg'], ['Turquie', 'Livre', 'Ankara']] Though the result is not a tuple in the list, it still sorts the data, hope this helps!