unsupported operand type(s) for -: 'int' and 'list'

Question

I am new to python programming with MySQL connectivity. I am working on my grade 12 project which is on the Stock Market or Primary Market aka New issue Market. This is the Purchase Module of my project.

If I run this code separately in pieces it runs without error but after putting it into combining all this error occurred.

unsupported operand type(s) for -: 'int' and 'list'

I don't know why it is happening

def converl(results,l):
#convert tuple into list
    for x in results:
        for z in x:
            l.append(z)
    return(l)



import mysql.connector as mycon
mydb = mycon.connect(user = 'root',
                         password = '',
                         host = 'localhost',
                         database = 'stockmarket')
cname =input('enter name of company to purchase shares ')
uname = 'amit'
sql = "select cname from companies"
cursor = mydb.cursor()
cursor.execute(sql)
results = cursor.fetchall()
l=[]       
t =  converl(results,l)
if cname in l:    
    try:

        csql = "select (purchased_shares) from purchase where cname = '%s'"%(cname)
        cursor = mydb.cursor()
        cursor.execute(csql)
        cresult = cursor.fetchall()
        s = len(cresult)
        res = []
        for i in cresult:
            t_sum = 0
            for j in i:
                t_sum += j
                res.append(t_sum)
                t = 0
                for z in range(0,s):
                    t = t + res[z]

        zsql = "select (issued_shares) from companies where cname = '%s'"%(cname)
        cursor.execute(zsql)
        zresult = cursor.fetchone()
        y = zresult[0]

        #finding shares left
        share_left = y - t
        print(share_left)
        if share_left>0:
            print(share_left,'available shares')

            no_of_shares = int(input('enter no of shares to be purchased '))

            if no_of_shares>zresult[0]:
                print('purchase shares should be equal to or less than shares left')
            else:
                csql = "select cno from companies where cname ='%s'"%(cname)
                cursor.execute(csql)
                cresult = cursor.fetchone()

                psql = "select rate from companies where cname ='%s'"%(cname)
                cursor.execute(psql)
                presult = cursor.fetchone()

                     #find total_paid
                total_paid = presult[0] * no_of_shares
                print(total_paid)

        #Insert into purchase
                sql = "insert into purchase (cno,username,cname,purchased_shares,total_paid)  values('%d','%s','%s','%d','%d')"%(cresult[0],uname,cname,no_of_shares,total_paid)
                cursor = mydb.cursor()
                cursor.execute(sql)

                #update companies table
                comsql = "update companies set sub_shares  = sub_shares + '%d' where cname ='%s'"%(no_of_shares,cname)
                cursor = mydb.cursor()
                cursor.execute(comsql)
                mydb.commit()
                print(no_of_shares,'Shares purchased')
                lnmenu()

                 #Insert into purchase


        else:
            print('No more shares left')
            tryagain()


    except Exception as expt:
        print(expt)

else:
    print('company not found')
    tryagain()

Answer 1

Finally, I solved it

Just change this

s = len(cresult)
res = []
for i in cresult:
    t_sum = 0
    for j in i:
        t_sum += j
        res.append(t_sum)
t = sum(res)