print_certain_nums.py

def pos_or_neg(value):
    if value > 0:
        print("positive")
    elif value < 0:
        print("negative")
        
print("expecting positive... ", end='')
pos_or_neg(3)
print("expecting negative... ", end='')
pos_or_neg(-8)
print("expecting nothing... ")
pos_or_neg(0)

def print_positives(list_of_ints): # list_of_ints = [5, 0, 10, -2, -8, 4]
    for value in list_of_ints: # 5, 0, 10, -2,...
        if value > 0:
            print(value)


def print_negatives(list_of_ints):
    for value in list_of_ints:
        if value < 0:
            print(value)

print("I'm on line 19")
a_list = [5, 0, 10, -2, -8, 4]
print_positives(a_list)
print("I'm on line 21")
other_list = [-5, 18, 21, -12, 0, 0, 2, 13]
print_positives(other_list)

def print_certain_numbers(list_of_ints, which_nums):
    if which_nums == 'positive':
        # print the ones that are more than zero
        print_positives(list_of_ints)
    if which_nums == 'negative':
        # print the ones that are less than zero
        print_negatives(list_of_ints)
    
print("I'm on line 40")
print_certain_numbers(other_list, "positive") # should print 18, 21, 2, 13
print("I'm on line 42")
print_certain_numbers(other_list, "negative") # should print -5, -12

turtle_bar_chart.py

import turtle

def draw_bar(t, height):
    """ Get turtle t to draw one bar, of height. """
    if height < 0:
        t.write(' ' + str(height))
    t.begin_fill()               # start filling this shape
    t.left(90)
    t.forward(height)
    if height >= 0:
        t.write(' ' + str(height))
    t.right(90)
    t.forward(40)
    t.right(90)
    t.forward(height)
    t.left(90)
    t.end_fill()                 # stop filling this shape
    
def main():
    data = [48, 0, 117, -200, 240, -160, 260, 220]
    max_height = max(data)
    num_bars = len(data)
    border = 10

    wn = turtle.Screen()             # Set up the window and its attributes
    wn.setworldcoordinates(0-border, 0-max_height-border, 40 * num_bars + border, max_height + border)
    wn.bgcolor("lightgreen")

    tess = turtle.Turtle()           # create tess and set some attributes
    tess.color("blue")
    tess.fillcolor("red")
    tess.pensize(3)

    for x in data:
        draw_bar(tess, x)

    wn.exitonclick()

if __name__ == "__main__":
    main()