#!/usr/bin/env python
# coding: utf-8

# In[1]:


# Section 4.8 -- Turtle with loops
import turtle
import time

#magic numbers
NUM_CIRCLES=30
START_RADIUS=5
OFFSET=15
ANIMATION_SPEED=1

#setup the turtle
turtle.speed(ANIMATION_SPEED)
turtle.hideturtle()

radius=START_RADIUS

for circle in range(NUM_CIRCLES):
  turtle.circle(radius)
  radius+=OFFSET
  turtle.penup()
  turtle.goto(turtle.xcor(),turtle.ycor()-OFFSET)
  turtle.pendown()
time.sleep(15)


# In[2]:


import turtle
import time

#magic numbers
NUM_CIRCLES=200
RADIUS=70
ANGLE_CHANGE=7
ANIMATION_SPEED=0

turtle.hideturtle()
turtle.speed(ANIMATION_SPEED)

for circle in range(NUM_CIRCLES):
  turtle.circle(RADIUS)
  turtle.left(ANGLE_CHANGE)

time.sleep(15)


# In[5]:


# Section 5.1 -- Functions
# idea of a function: group of statements that exist in a 
# program for doing a specific task
#
# Real-world example: pay calculator               <-- each
# - consider pay rate                              <-- of 
# - hours worked                                   <-- these
# - overtime pay                                   <-- can
# - benefits and tax withholdings                  <-- be 
# - local, county, state, federal taxes            <-- a
# - from all of this -- calculating the net income <-- function
#
# Benefits:
# - simpler code
# - reuse code
# - better testing
# - faster development
# - facilitate teamwork
#
# Two kinds
# 1. "void" functions -- execute statements and nothing else
#    ex. turtle.hideturtle()
# 2. "value-returning" functions -- execute statements and
#    also returns a value to the user to use for something
#    ex. print, input, float()
#
#
#
# Section 5.2 Defining and Calling Void Function
# Function names --- same rules as variable names (generally use verbs)
#
# Syntax
# def functionname():
#     stmt
#     stmt
#     etc

# Example
def message():
    print('Hello!')
    print('World!')

# notice -- merely defining a function does nothing
# you must "call" it for anything to happen

# we now have the command "message"
message()


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