Problem while using an arithmetic progression as indexes-CodePudding

My teacher gave me a question, which is supposed to give exact output he expects in an online python compiler:

Write a Python program to get the set of items purchased by the customers of a department store and print all the customer names in ascending order who have purchased a particular product based on the inputted product name.

I solved it as:

l1 = [] #list for the products 
l2 = [] #list for the people who were found to be using the product which was searched
l3 = [] #list for the names of people who bought the product
l5 = [] #list of all the products in the order they were bought
z = 0 #length of list l5
a = input('')#Number of people who wish to buy
b = input('')#Number of products which are to be bought
if a.isdigit() and b.isdigit():
    a = int(a) 
    b = int(b) 
    d1 = {} #Dictionary which stores the names and corresponding products.
    for i in range(1, a   1):
        name1 = input('')
        name = name1.replace("'", "")
        l3.append(name)
        l1 = [] #list for the products
        for j in range(1, b   1):
            prod1 = input('')
            prod = prod1.replace("'", "")
            l1.append(prod)
        d1[name] = l1
    for x in range(0, a):
        l5 = l5   d1[l3[x]]
    com1 = input('') #product name which is to be searched
    com = com1.replace("'", "")
    if com in l5:
        z = len(l5)
        for ind in range(z):
            if com == l5[ind]:
                for z2 in range(a):
                    z3 = ind - (z2*a)
                    if 0 < z3 < b:
                        l2.append(l3[z3])
                    else:
                        pass
        for m in range(len(l2)):
            print(l2[m])
    else:
        print("Invalid product")
else:
    print("Invalid input")

But the output only gives me the final name which was in common:

4 #Number of people
5 #Number of products
armaan
a
s
d
f
g
harry
d
c
f
v
g
michael
w
a
s
x
c
john
r
d
v
g
a
a #Product to be searched
john #Output

Process finished with exit code 0

While expected result is:

4 #Number of people
5 #Number of products
armaan
a
s
d
f
g
harry
d
c
f
v
g
michael
w
a
s
x
c
john
r
d
v
g
a
a #Product to be searched
armaan
michael
john #Output

Process finished with exit code 0

please help me with this question

CodePudding user response：

You can solve it like this -

people=int(input('')) #get number of people
prod_count=int(input('')) #get number of products
prods=[] #list containing the names of people and their corresponding products - [['armaan',['a','s','d','f','g']],...]
for i in range(people):
  name=input('') #name of the person
  products=[input('') for j in range(prod_count)] #this is a single line for looping the amount of times specified at the start in prod_count and storing the values in a list - ['a','s','d','f','g']
  prods.append([name,products]) #appending the name and the product list of the name to the main list
#print the final names
for i in prods: #iterating over the main list
  products=i[1] #getting the products - ['a','s','d','f','g']
  if input('') in products: #if the user inputted product name is in the list of products
    print(i[0])             #then print the name of the user