Semester Average Calculator.py

import sys
cat = {}
mp1 = {}
mp2 = {}

def page0():
  while True:
    c = input(f'\
[add] Add a category\n\
[continue] Continue to the next portion\n\
\n\
{", ".join(cat.keys())}\n> \
')
    if c == 'add':
      cat[input('Name of category?\n> ')] = int(input('Category weight?\n> '))
    elif c == 'continue':
      page1()

def page1():
  print("[== Marking Period 1 (MP1) ==]")
  for g in cat.keys():
    mp1[g] = [int(input(f'Maximum points for {g}?\n> ')), 
    int(input(f'Recieved points for {g}?\n> '))]

  print("[== Marking Period 2 (MP2) ==]")
  for g in cat.keys():
    mp2[g] = [int(input(f'Maximum points {g}?\n> ')),
    int(input(f'Recieved points for {g}?\n> '))]

  page2()

def page2():
  g_out = 0
  for g in cat.keys():
    g_out += (((mp1[g][1]+mp2[g][1])/(mp1[g][0]+mp2[g][1]))/100)*cat[g]
  print(f'Semester average: {g_out}')
  sys.exit()

try:
  page0()
except ValueError as ve:
  print(str(ve))