Add python_crash_tutorial Ch01

china-testing · china-testing · commit 2ca3c6e1e251 · 2018-06-11T16:31:56.000+08:00
diff --git a/python_crash_tutorial/Ch1/bounce.py b/python_crash_tutorial/Ch1/bounce.py
@@ -0,0 +1,20 @@
+# bounce.py
+# Bounce the turtle.
+
+from turtle import *
+
+def move(distance):
+    """Move forward, reversing direction at right side."""
+    forward(distance)
+    if xcor() > 320:
+        setheading(180)
+
+def main():
+    shape("circle")
+    penup()
+    speed(0)
+    for _ in range(100):
+        move(10)
+    exitonclick()
+    
+main()
diff --git a/python_crash_tutorial/Ch1/bowtie.py b/python_crash_tutorial/Ch1/bowtie.py
@@ -0,0 +1,18 @@
+# bowtie.py
+# Draw a bowtie
+
+from turtle import *
+
+pensize(7)
+penup()
+goto(-200, -100)
+pendown()
+fillcolor("red")
+begin_fill()
+goto(-200, 100)
+goto(200, -100)
+goto(200, 100)
+goto(-200, -100)
+end_fill()
+
+exitonclick()
diff --git a/python_crash_tutorial/Ch1/circle_at.py b/python_crash_tutorial/Ch1/circle_at.py
@@ -0,0 +1,20 @@
+# circle_at.py
+# Use a function to draw circles
+
+from turtle import *
+
+def circle_at(x, y, r):
+    """Draw circle with center (x, y) radius r."""
+    penup()
+    goto(x, y - r)
+    pendown()
+    setheading(0)
+    circle(r)
+
+circle_at(-200, 0, 20)
+begin_fill()
+circle_at(0, 0, 100)
+end_fill()
+circle_at(200, 0, 20)
+hideturtle()
+exitonclick()
diff --git a/python_crash_tutorial/Ch1/face.py b/python_crash_tutorial/Ch1/face.py
@@ -0,0 +1,29 @@
+# face.py
+# Draw a face using functions.
+
+from turtle import *
+
+def circle_at(x, y, r):
+    """Draw circle with center (x, y) radius r."""
+    penup()
+    goto(x, y - r)
+    pendown()
+    setheading(0)
+    circle(r)
+
+def eye(x, y, radius):
+    """Draw an eye centered at (x, y) of given radius."""
+    circle_at(x, y, radius)
+    
+def face(x, y, width):
+    """Draw face centered at (x, y) of given width."""
+    circle_at(x, y, width/2)
+    eye(x - width/6, y + width/5, width/12)
+    eye(x + width/6, y + width/5, width/12)
+    
+def main():
+    face(0, 0, 100)
+    face(-140, 160, 200)
+    exitonclick()
+        
+main()
diff --git a/python_crash_tutorial/Ch1/mycircle.py b/python_crash_tutorial/Ch1/mycircle.py
@@ -0,0 +1,12 @@
+# mycircle.py
+# Mimic circle() with adaptive radius.
+
+def mycircle(radius):
+    """Draw circle as polygon."""
+    if radius < 20:
+        sides = 10
+    elif radius < 100:
+        sides = 30
+    else:
+        sides = 50
+    polygon(sides, 6.28*radius/sides)
diff --git a/python_crash_tutorial/Ch1/polygon.py b/python_crash_tutorial/Ch1/polygon.py
@@ -0,0 +1,18 @@
+# polygon.py
+# Draw regular polygons
+
+from turtle import *
+
+def polygon(n, length):
+    """Draw n-sided polygon with given side length."""
+    for _ in range(n):
+        forward(length)
+        left(360/n)
+        
+def main():
+    """Draw polygons with 3-9 sides."""
+    for n in range(3, 10):
+        polygon(n, 80)
+    exitonclick()
+    
+main()
diff --git a/python_crash_tutorial/Ch1/randomwalk.py b/python_crash_tutorial/Ch1/randomwalk.py
@@ -0,0 +1,18 @@
+# randomwalk.py
+# Draw path of a random walk.
+
+from turtle import *
+from random import randrange
+
+def random_move(distance):
+    """Take random step on a grid."""
+    left(randrange(0, 360, 90))
+    forward(distance)
+    
+def main():
+    speed(0)
+    while abs(xcor()) < 200 and abs(ycor()) < 200:
+        random_move(10)
+    exitonclick()
+    
+main()
diff --git a/python_crash_tutorial/Ch1/spiral.py b/python_crash_tutorial/Ch1/spiral.py
@@ -0,0 +1,18 @@
+# spiral.py
+# Draw spiral shapes
+
+from turtle import *
+
+def spiral(firststep, angle, gap):
+    """Move turtle on a spiral path."""
+    step = firststep
+    while step > 0:
+        forward(step)
+        left(angle)
+        step -= gap
+
+def main():
+    spiral(100, 71, 2)
+    exitonclick()
+
+main()
diff --git a/python_crash_tutorial/Ch1/square.py b/python_crash_tutorial/Ch1/square.py
@@ -0,0 +1,15 @@
+# square.py
+# Draw a square
+
+from turtle import *
+
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+forward(100)
+left(90)
+
+exitonclick()
