[Tutor] printing value returning from a Class

[Kalle Svensson]

Hello!

On 9/13/07, Varsha Purohit <varsha.purohit at gmail.com> wrote:
> Hello friends,,
>           I have a problem in displaying data  which i have invoked from
> class. City is the name of the class which i havent displayed here. There is
> another script using that class. It has a function name setCities which
> takes a text file as argument. Text file contains name of the city, x and y
> location. there are 4 datas in 4 different lines. Code is as follows.
>
> import City
>
> def setCities(inFile):
>     # puts city.txt content into City class objects
>     # the field order of input file is: name x y   x, y are integers. data
> are in newlines.
>     f = open(inFile, 'r')
>     body = f.readlines()
>     f.close()
>     cities = []  # list of cities
>     for row in body:
>         cityData = row.strip().split()
>         cityName = cityData[0]
>         cityX = cityData[1]
>         cityY = cityData[2]
>         newCity = City(cityName, cityX, cityY)  # city class is invoked
>         cities.append(newCity)
>     return cities
>
>
> abc = setCities("C:\MS\sem5\Lab2_scripts\cities.txt")  #
> setCities function will return the array with values read from the file.
> print abc
>
> I am getting output like
> [<city.City instance at 0x023E82D8>, <city.City instance at 0x023E8300>,
> <city.City instance at 0x023E8350>, <city.City instance at 0x023E83C8>]
>
> I want the data and not the instance... what should i do ??

Well, that depends on the City class. When you print a list, it just
calls repr() on each item in the list and prints that. Now, suppose
there is a method printCity() in the City class for printing the city
data. In that case you should probably just loop over the list of
instances and call the method, like this:

>>> abc = setCities("city file")
>>> for city in abc:
...     city.printCity()

If there is no such method, maybe you can extract the data from the
class and write your own printing function, or modify the class to add
one.

HTH,
  Kalle