def main():
seatList = [
    [50,50,50,50,50],
    [40,45,45,45,40],
    [30,35,35,35,30],
    [20,20,20,20,20],
    [10,10,10,10,10],
]
cont = "y"
while cont.lower() == "y":
    print("Here is the seating arrangement:")
    availableSeat = seatPrinter(seatList)
    totalRow = int(len(seatList)) - 1
    totalColumn = int(len(seatList[0])) - 1
    seatRow = int(input("Please enter a row number (1 to %d):"%totalRow))
    seatColumn = int(input("Please enter a seat number (1 to %d):"%totalColumn))
    seatStatus = seatAvailable(seatList, seatRow, seatColumn)
    cont = input("Would you like to reserve another seat?(Y/N)")

def seatPrinter(seats):
    for i in range(len(seats[0])):
        print(seats[i])

def seatAvailable(seats, row, column):
    for i in range(len(seats)):
        for j in range(len(seats)):
            if seats[i][j] is not 'SS':
                seats[i][j] = 'SS'
                print("Your seat is in row %d seat number %d"%(i+1, j+1))
                return
            else:
                print("Sorry, that seat isn't available.")
                return

main()

Here is the seating arrangement:
[50, 50, 50, 50, 50]
[40, 45, 45, 45, 40]
[30, 35, 35, 35, 30]
[20, 20, 20, 20, 20]
[10, 10, 10, 10, 10]
Please enter a row number (1 to 4):1
Please enter a seat number (1 to 4):1
Your seat is in row 1 seat number 1
Would you like to reserve another seat?(Y/N)y
Here is the seating arrangement:
['SS', 50, 50, 50, 50]
[40, 45, 45, 45, 40]
[30, 35, 35, 35, 30]
[20, 20, 20, 20, 20]
[10, 10, 10, 10, 10]
Please enter a row number (1 to 4):1
Please enter a seat number (1 to 4):2
Sorry, that seat isn't available.
Would you like to reserve another seat?(Y/N)