Exercise 8-13 Powerball Lottery: Frequency of Numbers
# Named constants
LOTTERY_NUMBERS = 69
POWERBALL_NUMBERS = 26
def main():
# Get a list of all the lottery numbers.
lottery_list = get_numbers()
# Create lists to hold each number’s frequency. The lists
# are initialized with each element set to 0.
reg_frequency = [0] * (LOTTERY_NUMBERS + 1)
pb_frequency = [0] * (POWERBALL_NUMBERS + 1)
# Get the frequency of each regular number.
for i in range(len(lottery_list[0])):
# Get the next number in the list.
num = lottery_list[0][i]
# Increment that number’s frequency.
reg_frequency[num] += 1
# Get the frequency of each PowerBall number.
for i in range(len(lottery_list[1])):
# Get the next number in the list.
num = lottery_list[1][i]
# Increment that number’s frequency.
pb_frequency[num] += 1
# Display the frequency of each regular number.
print(‘Frequencies of the regular numbers’)
print(‘———————————-‘)
for i in range(1, len(reg_frequency)):
print(i, ‘was chosen’, reg_frequency[i], ‘times.’)
# Display the frequency of each PowerBall number.
print(‘\nFrequencies of the PowerBall numbers’)
print(‘———————————-‘)
for i in range(1, len(pb_frequency)):
print(i, ‘was chosen’, pb_frequency[i], ‘times.’)
# The get_numbers function returns a 2-dimensional list with
# two elements. The first element is a list of the regular lottery
# numbers, and the 2nd element is a list of the PowerBall numbers.
def get_numbers():
# Open the lottery number file.
pblottery_file = open(‘pbnumbers.txt’, ‘r’)
# Read the file contents into a list.
work_list = pblottery_file.readlines()
# Close the file.
pblottery_file.close()
# Strip the newline from each element.
for i in range(len(work_list)):
work_list[i] = work_list[i].rstrip(‘\n’)
# Split each element into individual numbers, and store the
# individual regular numbers in a list named lotto_nums, and
# the individual PowerBall numbers in a list named pb_numbers.
lotto_nums = []
pb_numbers = []
for i in range(len(work_list)):
number_set = work_list[i].split()
for j in range(len(number_set) – 1):
lotto_nums.append(int(number_set[j]))
pb_numbers.append(int(number_set[len(number_set)-1]))
pblottery = [[],[]]
pblottery[0] = lotto_nums
pblottery[1] = pb_numbers
# Return the pblottery list.
return pblottery
main()