class Customer:

    # constructor
    def __init__(self,cnum,name,cty):
        self.cno = cnum
        self.cname = name
        self.city = cty
    
    # getter
    def get_cno(self):
        return self.cno

    # getter
    def get_cname(self):
        pass

    # getter
    def get_city(self):
        return self.city

    # setter
    def set_cno(self,cnum):
        pass

    # setter
    def set_cname(self,name):
        pass

    # setter
    def set_city(self,cty):
        pass

    # return string representation of Customer object
    def __str__(self):  # same as toString() method in Java
        result = ""
        result = result + "CNO:\t" + str(self.cno) + "\n"
        result = result + "CNAME:\t" + self.cname + "\n"
        result = result + "CITY:\t" + self.city + "\n"
        return result

c1 = Customer(9000,"K Jones","Atlanta")
print(c1)

CNO:	9000
CNAME:	K Jones
CITY:	Atlanta

class Customers():

    # constructor
    def __init__(self):
        self.customers = {}

    # add Customer object c to dictionary; do not add if customer number already present
    def add_customer(self,cno,c):
        if cno not in self.customers:
            self.customers[cno] = c

    # return Customer object corresponding to cno; return None if no customer with cno
    def get_customer(self,cno):
        pass

    # return a list of all customer numbers
    def get_cnos(self):
        pass
        
    # return string representation of Customers object
    def __str__(self):
        result = ""
        for cno in self.customers:
            result = result + str(self.customers[cno]) + "\n"
        return result

class Part:

    # constructor
    def __init__(self,pnum,name,price):
        self.pno = pnum
        self.pname = name
        self.price = price
    
    # getter
    def get_pno(self):
        return self.pno

	# getter
    def	get_pname(self):
        pass

	# getter
    def get_price(self):
        pass

    # setter
    def set_pno(self,pnum):
        pass

	# setter
    def set_pname(self,name):
        pass

	# setter
    def set_price(self,price):
        pass

	# return string representation of Part object
    def __str__(self):  # same as toString() method in Java
        result = ""
        result = result + str(self.pno) +"\t"
        result = result + self.pname +"\t\t"
        result = result + str(self.price)
        return result

class Parts():

    # constructor
    def __init__(self):
        self.parts = {}

    # add Part object p to dictionary; do not add if part number already exists
    def add_part(self,p):
        if p.get_pno() not in self.parts:
            self.parts[p.get_pno()] = p

    # return Part object for pno; return None if no part with pno
    def get_part(self,pno):
        pass

    # return a list of all part numbers
    def get_pnos(self):
        pass
        
    # return string representation of Parts object
    def __str__(self):
        result = ""
        for pno in self.parts:
            result = result + str(self.parts[pno]) + "\n"
        return result

# load_data function
dname = "data"
fname = dname + "/customers.dat"
with open(fname) as f:
    data = f.read().splitlines()
customers = Customers()
for line in data:
    xs = line.split(":")
    c = Customer(int(xs[0]),xs[1],xs[2])
    customers.add_customer(c.get_cno(),c)
print(customers)

fname = dname + "/parts.dat"
with open(fname) as f:
    data = f.read().splitlines()
parts = Parts()
for line in data:
    xs = line.split(":")
    p = Part(int(xs[0]),xs[1],float(xs[2]))
    parts.add_part(p)
print(parts)

CNO:	1111
CNAME:	John Smith
CITY:	Atlanta

CNO:	2222
CNAME:	Alice Stewart
CITY:	Chicago

CNO:	3333
CNAME:	Doug Jones
CITY:	Montgomery


1000	Nut		2.5
1001	Bolt		3.0
1002	Screw		1.25
1003	Crankshaft		12.0
1004	Cylinder		8.0
1005	Casing		22.0