CODEWITHSUNDEEP
pythonclassoopobject
Programmer
Programmer

Reputation: 1294

Creating multiple classes from list of lists

I have a list of lists as follows:

list = [['SYDNEY', 'to', 'SAN FRANCISCO'], ['SYDNEY', 'from' 'AUCKLAND'], ['HONG KONG', 'to', 'BEIJING'], ['TOKYO' 'to', 'SEOUL'], ['SAN FRANCISCO', 'from', 'LONDON'], ['SYDNEY', 'to', 'SHANGHAI'], ['KL', 'to', 'SYDNEY']]

I also have a class called 'City' 

class City:

    def __init__(self, name):
        self.cityName= name
        self.to_or_from = []
        self.to_or_from_city = []

How can I use the list to create objects for each city. For example, for Sydney, the object should look like this: 

cityName = Sydney
to_or_from = ['to', 'from', 'to']
to_or_from_city = ['SAN FRANCISCO', 'AUCKLAND', 'SHANGHAI']

Please note that there is no need to consider KL in the Sydney object, however, the KL object should contain Sydney as follows: 

cityName = KL
to_or_from = ['to']
to_or_from_city = ['SYDNEY']

In other words, if we have ['City1', 'to', 'City2'], then the City2 object does not need to contain a 'from' City1.

Upvotes: 0

Views: 312

Answers (1)

stovfl
stovfl

Reputation: 15513

Question: How can I use the _list to create a class City object for each city

_list = [['SYDNEY', 'to', 'SAN FRANCISCO'], 
         ['SYDNEY', 'from', 'AUCKLAND'], 
         ['HONG KONG', 'to', 'BEIJING'], 
         ['TOKYO', 'to', 'SEOUL'], 
         ['SAN FRANCISCO', 'from', 'LONDON'], 
         ['SYDNEY', 'to', 'SHANGHAI'], 
         ['KL', 'to', 'SYDNEY']
        ]

class City:
    def __init__(self, name):
        self.cityName= name
        self.to_or_from = []
        self.to_or_from_city = []

    def append(self, relation):
        c1, r, c2 = relation
        self.to_or_from.append(r)
        self.to_or_from_city.append(c2)

    def __str__(self):
        return 'City:{}, {}'.format(self.to_or_from, self.to_or_from_city)

cities = {}
for relation in _list:
    name = relation[0]
    cities.setdefault(name, City(name)).append(relation)

for name, city  in cities.items():
    print('{}:{}'.format(name, city))

Output:

SYDNEY:City:['to', 'from', 'to'], ['SAN FRANCISCO', 'AUCKLAND', 'SHANGHAI']
HONG KONG:City:['to'], ['BEIJING']
TOKYO:City:['to'], ['SEOUL']
SAN FRANCISCO:City:['from'], ['LONDON']
KL:City:['to'], ['SYDNEY']

Upvotes: 1

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