dangoldin

import csv, re
from collections import namedtuple, Counter

cols = ['date', 'dow', 'hours_slept', 'mood_morning', 'mood_day', 'mood_evening', 'breakfast', 'lunch', 'dinner', 'drinks', 'snacks', 'coffee', 'weight']

StatDay = namedtuple('StatDay', cols)

RE_NON_WORD = re.compile('\W+')
RE_NUM = re.compile('\d+')

dangoldin

N = number of passengers
p = ticket price
c = % of passengers that will be checked for a ticket
v = % of passengers that are violators
F = fine

Np = Np(1-c)(1-v) + Npc(1-v) + Ncv*F

Solving for F, we get that F = p/c.