Here is your code. I'm assuming you're using python 3 based on the your use of print() and input():
import random
def main():
#random.seed() --> don't need random.seed()
#Prompts the user to enter the number of tickets they wish to play.
#python 3 version:
tickets = int(input("How many lottery tickets do you want?\n"))
#Creates the dictionaries "winning_numbers" and "guess." Also creates the variable "winnings" for total amount of money won.
winning_numbers = []
winnings = 0
#Generates the winning lotto numbers.
for i in range(tickets * 5):
#del winning_numbers[:] what is this line for?
randNum = random.randint(1,30)
while randNum in winning_numbers:
randNum = random.randint(1,30)
winning_numbers.append(randNum)
print(winning_numbers)
guess = getguess(tickets)
nummatches = checkmatch(winning_numbers, guess)
print("Ticket #"+str(i+1)+": The winning combination was",winning_numbers,".You matched",nummatches,"number(s).\n")
winningRanks = [0, 0, 10, 500, 20000, 1000000]
winnings = sum(winningRanks[:nummatches + 1])
print("You won a total of",winnings,"with",tickets,"tickets.\n")
#Gets the guess from the user.
def getguess(tickets):
guess = []
for i in range(tickets):
bubble = [int(i) for i in input("What numbers do you want to choose for ticket #"+str(i+1)+"?\n").split()]
guess.extend(bubble)
print(bubble)
return guess
#Checks the user's guesses with the winning numbers.
def checkmatch(winning_numbers, guess):
match = 0
for i in range(5):
if guess[i] == winning_numbers[i]:
match += 1
return match
main()