Update turtle.md

Author: sbtries

1 Python/labs/optional_labs/turtle.md

@@ -1,71 +1,202 @@
-# lab01_turtle.py
-
-import turtle
-
-# right arm
-turtle.setposition(0, 0)
-turtle.left(45)
-turtle.forward(35)
-
-# left arm
-turtle.penup()
-turtle.setposition(0, 0)
-turtle.pendown()
-turtle.left(90)
-turtle.forward(35)
-
-# body
-turtle.penup()
-turtle.setposition(0, 35)
-turtle.pendown()
-turtle.left(135)
-turtle.forward(70)
-
-# right leg
-turtle.left(45)
-turtle.forward(45)
-turtle.penup()
-
-# left leg
-turtle.setposition(0, -35)
-turtle.pendown()
-turtle.right(90)
-turtle.forward(45)
-
-# left eye
-turtle.fillcolor('green')
-turtle.begin_fill()
-turtle.penup()
-turtle.setposition(-14, 70)
-turtle.pendown()
-turtle.circle(5)
-turtle.end_fill()
-
-# right eye
-turtle.fillcolor('green')
-turtle.begin_fill()
-turtle.penup()
-turtle.setposition(8, 70)
-turtle.pendown()
-turtle.circle(5)
-turtle.end_fill()
-
-# mouth
-turtle.penup()
-turtle.setposition(-6, 45)
-turtle.left(135)
-turtle.pendown()
-turtle.forward(20)
-
-# head
-turtle.penup()
-turtle.setposition(0, 35)
-turtle.pendown()
-turtle.circle(25)
-
-# nose
-turtle.penup()
-turtle.setposition(-5, 52)
-turtle.right(145)
-
-turtle.done()
+# Lab 1: Turtle
+
+## Explanation
+
+Turtle is a python `module` that allows us to move a virtual turtle around the screen using programming statements. This turtle has a position and a heading. Below are a list of commands, you can more in the [turtle docs](https://docs.python.org/3.6/library/turtle.html).
+
+- `forward(distance)` moves the turtle forward the given number of pixels 
+- `left(angle)` and `right(angle)` turns the turtle left or right by the given angle (in degrees)
+- `color(color_name)` sets the pen's color, which can be `penup()` `penup()` `penup()`
+- `penup()` raises the pen, a line won't be drawn when the turtle moves, `pendown()` lowers the pen again
+
+- `setposition(x, y)` moves the turtle to the given position
+
+- `fillcolor(color_name)` sets the fill color, `begin_fill()` indicates you'd like to begin filling in whatever you draw, `end_fill()` actually fills the shape in.
+
+Use these functions to draw a stick figure with a head, body, two arms, and two legs. Once you're done, go through the examples below and create your own drawing.
+
+## Examples
+
+
+### Drawing a Square 
+
+```python
+from turtle import *
+
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+
+done()
+
+```
+
+### Filling in a Square 
+
+```python
+from turtle import *
+
+fillcolor('red')
+begin_fill()
+
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+
+end_fill()
+
+done()
+
+```
+
+### Drawing a Star 
+
+```python
+from turtle import *
+
+forward(100)
+right(144)
+forward(100)
+right(144)
+forward(100)
+right(144)
+forward(100)
+right(144)
+forward(100)
+
+done()
+
+```
+
+
+### Drawing a Square with a Loop
+
+```python
+from turtle import *
+
+i = 0
+while i < 4:
+    forward(100)
+    left(90)
+    i = i + 1
+
+done()
+```
+
+### Drawing a Circle with a Loop
+```python
+from turtle import *
+
+i = 0
+while i < 100:
+    forward(2)
+    left(360/100)
+    i = i + 1
+
+done()
+```
+
+### Drawing a Staircase
+
+```python
+from turtle import *
+
+i = 0
+while i < 4:    
+	forward(100)
+	left(90)
+	forward(100)
+	right(90)
+	i = i + 1
+done()
+```
+
+
+### Filling in a Square 
+
+```python
+from turtle import *
+
+fillcolor('red')
+begin_fill()
+
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+
+end_fill()
+
+done()
+
+```
+
+### Draw an N-Sided figure
+```python
+from turtle import *
+
+edge_length = 100
+n_sides = 5
+
+i = 0
+while i < n_sides:
+	forward(edge_length/n_sides)
+	right(360/n_sides)
+	i = i + 1
+
+done()
+
+```
+
+
+### 8-Sided Spiral
+
+```python
+from turtle import *
+
+fillcolor('blue')
+
+n_sides = 8
+edge_length = 0
+
+i = 0
+begin_fill()
+while i < 150:
+	forward(edge_length)
+	right(360/n_sides)
+	i = i + 1
+	edge_length = edge_length + 1
+end_fill()
+done()
+
+```
+
+### Expanding Star
+
+```python
+from turtle import *
+
+edge_length = 0
+i = 0
+while i < 100:
+	forward(edge_length)
+	right(144)
+
+	edge_length += 4
+
+done()
+```