How to solve enterprise software problem in python?

Question

Here, I have developed the enterprise software in python. I have a database and in that I have bill_details table and paid_details table. The bill_details table will have amount to be paid,date and name. In paid_details table has name and paid amount and this is the scenario.

If the user want to know how much the payment dues are there then I should print the due amount.

For eg. bill_details

name        amt_pending         date

xyz          100               20-09-2020
xyz          50               21-09-2020
xyz          200               22-09-2020
xyz          20               23-09-2020

In paid details table paid_details

name          paid_amt        date

xyz             100          21-09-2020
xyz             50           22-09-2020

and these are my tables. I need output like this

xyz

22-09-2020      200
23-09-2020      20

I need to tally the pending amount with the paid amount and display the pending amount. How can I achieve this? I have tried it with list but that worked but I can't map those dates with the pending amount. Please help me with this.

I have added the code that I have tried

date  = [1,2,3,4,5,6,7,8,9,10]
pending  = [10,100,5,6]
paid  = [10,100,5]
c  = pending.copy()

# clen=len(c)

for i in range(len(paid)):
    print(paid[i],pending[i],i)
    # alen = len(a)

    if(paid[i]-pending[i]==0):
        c.remove(paid[i])
    else:
        c[i] = pending[i] - paid[i]
        # print(a[-1]-b[i])
        

print(pending)

Answer 1

try this:

fields = ['Name', 'amt_pending', 'date', 'paid_amt'] 
  
rows = [ ['xyz', 100, '20-09-2020', 100], 
         ['xyz', 50, '21-09-2020', 50], 
         ['xyz', 200, '22-09-2020', 0]] 
  



for i in rows:
            
    if i[1] == i[3]:
        print('no pending remaining')
    else:
        a = i[1] - i[3]
        print("pending amount is: " + str(a) + ' on ' + str(i[2]))