main.py

import numpy as np
import random
from matplotlib import pyplot as plt
from Person import Person

# Factors that affect the population

# 1. Starting Population
# 2. Infant mortality
# 3. Food
# 4. Fertility x and Fertility y
# 5. Healthcare
# 6. Agriculture
# 7. Chance of disaster
# 8. Age of death

startingPopulation = 50
infantMortality = 25
food = 0
agriculture = 5
disasterChance = 10
fertilityX = 18
fertilityY = 35
youthMortality = 45
ageOfDeath = 80
healthcare = 95
warDeaths = 2

populationList = []

# This function will run every year. It will produce food for the next year and if not enough able people produce
# food, people will die from starvation.

def harvest(food, agriculture):
    ablePeople = 0
    for person in populationList:
        if person.age > 18:
            ablePeople += 1
        
    food += ablePeople * agriculture
    
    if food < len(populationList):
        del populationList[0: int(len(populationList) - food)]
    else:
        food -= len(populationList)

# This function will increase the population based on the given conditions

def reproduce(fertilityX, fertilityY):
    for person in populationList:
        if person.age > fertilityX and person.age < fertilityY and random.randint(0,5) == 1 and random.randint(0,100) > 5:
            populationList.append(Person(0))


# This function will kickstart the simulation by adding the starting population
# to the populationList

def beginSim():
    for x in range(startingPopulation):
        populationList.append(Person(random.randint(18,50)))

# Begins Simulation by creating 50 people
beginSim()

popTrack = []
def runYear(food, agriculture, fertilityX, fertilityY, infantMortality, healthcare, warDeaths):
    harvest(food, agriculture)
    reproduce(fertilityX, fertilityY)
    
    for person in populationList:
        if person.age>ageOfDeath:
            populationList.remove(person)
        else:
            person.age += 1
    
    # There's a 10% chance of disaster happening
    if random.randint(0,100)<disasterChance:
        del populationList[0:int(random.uniform(0.05,0.1)*len(populationList))]

    # There's a 5% chance of people dying due to diseases (even before 80)
    if random.randint(0,100)>healthcare:
        del populationList[0:int(random.uniform(0.05,0.1)*len(populationList))]
        
    # War related deaths
    if random.randint(0,100)<warDeaths:
        del populationList[0:int(random.uniform(0.01, 0.02)*len(populationList))]
        
    popTrack.append(len(populationList))
    infantMortality *= 0.9
    healthcare *= 1.1
    warDeaths *= 0.9
    return infantMortality, healthcare, warDeaths

while len(populationList)<100000 and len(populationList) > 1:
    infantMortality, healthcare, warDeaths = runYear(food, agriculture, fertilityX, fertilityY, infantMortality, healthcare, warDeaths)

popTrack_np = np.array(popTrack)
from matplotlib import pyplot as plt

plt.plot(range(len(popTrack_np)), popTrack_np)
plt.title("Population vs Year")
plt.xlabel("Year")
plt.ylabel("Population")
plt.show()