Examples from python lessons I taught.

teaching_python.py

# Created By: Justin Meiners (2017)
# simple calculations
# -------------------------------

import math

def volume_cone(radius, height):
    volume = math.pi * (radius**2.0) * (height / 3.0)
    return volume

radius = 30.0
height = 20.0

print(type(math.pi))
volume = volume_cone(radius, height)
print(volume)


# integration
# -------------------------------
import math

def integral(f_x, min, max, iterations):
    width = (max - min) / iterations

    area_total = 0.0

    for i in range(1, iterations + 1):
        xi = width * i
        yi = f_x(xi)
        area_total = area_total + width * yi

    return area_total

print(integral(math.sin, 0.0, 5.0, 2000))

# processing some CSV data
# -------------------------------

import csv
import math

with open('data.csv', 'r') as csvfile:
    data_reader = csv.reader(csvfile)

    headers = None

    for row in data_reader:
        if not headers:
            headers = row
            print("%s\t%s\tmean" % (headers[0], headers[1]) )
            continue

        sample_id = row[0]
        analyte_name = row[1]

        conc1 = float(row[2])
        conc2 = float(row[3])
        conc3 = float(row[4])

        total = conc1 + conc2 + conc3
        mean = total / 3.0

        print("%s\t%s\t%f" % (sample_id, analyte_name, mean) )
        
        
# functions, state and global variables
# -------------------------------

import random

apple_count = 10
yogurt_count = 8

def needs_groceries():
    if apple_count < 3 or yogurt_count < 2:
        return True
    else:
        return False

def hannah_eat():
    global yogurt_count
    global apple_count

    if yogurt_count >= 1:
        yogurt_count = yogurt_count - 1

    if apple_count >= 2:
        apple_count = apple_count - 2

def justin_eat():
    global yogurt_count
    global apple_count

    if yogurt_count >= 2:
        yogurt_count = yogurt_count - 2

    if apple_count >= 4:
        apple_count = apple_count - 4

def meal():
    if needs_groceries():
        print("Get to WinCo!")
        return

    dice_roll = random.sample([False, True], 1)

    if dice_roll[0]:
        print("Justin")
        justin_eat()
    else:
        print("Hannah")
        hannah_eat()

    print(apple_count)
    print(yogurt_count)

meal()
meal()
meal()
meal()


# physical simulations
# -------------------------------

import math

class Ball:
    def __init__(self, x, y, angle, speed):
        self.x = x
        self.y = y
        self.angle_rad = math.radians(angle)
        self.vx = math.cos(self.angle_rad) * speed
        self.vy = math.sin(self.angle_rad) * speed

def integrate(ball, dt):
    gravity = -9.81

    ball.vy += gravity * dt
    ball.x += ball.vx * dt
    ball.y += ball.vy * dt

def simulate(ball):
    while ball.y > 0.0:
        dt = 1.0 / 30.0
        integrate(ball, dt)
        coordinate = str(ball.x) + "\t" + str(ball.y)
        print(coordinate)

myBall = Ball(0.0, 1.0, 45.0, 19.0)
myBall2 = Ball(0.0, 2.0, 60.0, 19.0)

simulate(myBall)
print('---------------------')
simulate(myBall2)


# Tic Tac Toe
# -------------------------------

from __future__ import print_function
# 0 = nothing, 1 = x, 2 = 0

BLANK = 0
X = 1
O = 2

board = [BLANK] * 9

def print_board(board_to_print):
    for i in range(0, 9):
        cell = board_to_print[i]
        character = '_'
        if cell == X:
            character = 'x'
        elif cell == O:
            character = 'o'
        print(character, end=' ')
        if i == 2:
            print('\n')
        elif i == 5:
            print('\n')
        elif i == 8:
            print('\n')

def get_player_move(board_to_edit, turn):
    if turn == X:
        player_name = "X's"
    elif turn == O:
        player_name = "O's"
    message = player_name + " where would you like to play? "
    cell = int(input(message)) - 1
    if cell > 9 or cell < 1 or board_to_edit[cell] != BLANK:
        return False
    else:
        board_to_edit[cell] = turn
        return True

current_turn = X
while True:
    valid = get_player_move(board, current_turn)
    if not valid:
        print("Can't move there!")
        continue

    print(' \n')
    print_board(board)
    if current_turn == X:
        current_turn = O
    elif current_turn == O:
        current_turn = X