How to read the contents of a csv file into a class with each csv row as a class instance

Question

I'm a Python newbie, and I've been struggling with a class assignment for days. I have a csv file that contains data as such:

id,latitude,longitude,city,label,yr1970,yr1975,yr1980,yr1985,yr1990,yr1995,yr2000,yr2005
1,35.6832085,139.8089447,Tokyo,Tokyo,23.3,26.61,28.55,30.3,32.53,33.59,34.45,35.62

There are about 40 rows in this file, each containing data related to a world city. As you can see, the top row is the header. I am supposed to create a class in Python and read the csv file into the class, where every row becomes an instance of the class. I am then to store the class instances in a list. I've been able to create one instance where all of the data is stored, but I can't seem to create an instance for each row (and I obviously do not want to do it manually).

Here's what I've got so far:

import csv
Cities = []


with open('filepath','rb') as f:
cityList = csv.reader(f)
for row in cityList:
    if row != 'label':
        for row in cityList:
            citysName = row[3]


            class City:

                def __init__(self, cityName=row[3], Label=row[4], Lat=row[1],
                         Lon=row[2], yr1970=row[5], yr1975=row[6], yr1980=row[7],
                             yr1985=row[8], yr1990=row[9], yr1995=row[10], yr2000=row[11],
                             yr2005=row[12], yr2010=row[13]):
                    self.cityName = cityName
                    self.label = Label
                    self.lat = Lat
                    self.lon = Lon
                    self.yr1970 = yr1970
                    self.yr1975 = yr1975
                    self.yr1980 = yr1980
                    self.yr1985 = yr1985
                    self.yr1990 = yr1990
                    self.yr1995 = yr1995
                    self.yr2000 = yr2000
                    self.yr2005 = yr2005
                    self.yr2010 = yr2010

            citysName = City()

            Cities.append(citysName.cityName)
            Cities.append(citysName.label)
            Cities.append(citysName.lat)
            Cities.append(citysName.lon)
            Cities.append(citysName.yr1970)
            Cities.append(citysName.yr1975)
            Cities.append(citysName.yr1980)
            Cities.append(citysName.yr1985)
            Cities.append(citysName.yr1990)
            Cities.append(citysName.yr1995)
            Cities.append(citysName.yr2000)
            Cities.append(citysName.yr2005)
            Cities.append(citysName.yr2010)

        print Cities

Again, I'm quite new with Python (and coding in general), and I realize this code is not good, but I'm having a lot of difficulty finding tips for reading csv files into a Python class.

Answer 1

You can try this:

import csv
class City:
   def __init__(self, row, header):
        self.__dict__ = dict(zip(header, row))

data = list(csv.reader(open('file.csv')))
instances = [City(i, data[0]) for i in data[1:]]

However, since you mentioned that there are many rows, you may want to create an id for each city that will act as your string representation in the list:

import csv
class City:
   def __init__(self, row, header, the_id):
       self.__dict__ = dict(zip(header, row)) 
       self.the_id = the_id
   def __repr__(self):
       return self.the_id

data = list(csv.reader(open('file.csv')))
instances = [City(a, data[0], "city_{}".format(i+1)) for i, a in enumerate(data[1:])]

Your output will be a listing like this:

[city_1, city_2, city_3...]

And any attributes can be called like so:

instances[1].latitude

Regarding your recent comment, to access city attributes by city name, you can slightly restructure instances:

instances = {a[3]:City(a, data[0], "city_{}".format(i+1)) for i, a in enumerate(data[1:])}