Passed pep8, added some art files.

random_art.py

@@ -1,19 +1,94 @@
 import random
+from math import sin, cos, pi, tan, hypot, e
 
 # Your job is to create better version of create_expression and
 # run_expression to create random art.
 # Your expression should have a __str__() function defined for it.
 
 
+def cube(a):
+    return a ** 3
+
+
+def avg(x, y):
+    return x + y / 2
+
+
+def wut(x, y):
+    return (x**10) + (y**3)
+
+
+def wtf(x, y, z):
+    return (x**3) + (y**4) + (z**5)
+
+
+def omg_wtf(prob):
+    return("wtf(" + str(generate_expression(prob**2)) + ','
+                  + str(generate_expression(prob**2)) + ','
+                  + str(generate_expression(prob**2)) + ")")
+
+
+def wut_wut(prob):
+    return("wut(" + str(generate_expression(prob**2)) + ','
+                  + str(generate_expression(prob**2)) + ")")
+
+
+def sin_pi(prob):
+    return "sin(pi*" + str(generate_expression(prob**2)) + ")"
+
+
+def tan_pi(prob):
+    return "tan(pi*" + str(generate_expression(prob**2)) + ")"
+
+
+def cube_pi(prob):
+    return "cube(pi*" + str(generate_expression(prob**2)) + ")"
+
+
+def cos_pi(prob):
+    return "cos(pi*" + str(generate_expression(prob**2)) + ")"
+
+
+def avg_num(prob):
+    return ("avg(" + str(generate_expression(prob**2)) + ','
+                   + str(generate_expression(prob**2)) + ")")
+
+
+def hypot_num(prob):
+    return ("hypot(" + str(generate_expression(prob**2)) + ','
+                     + str(generate_expression(prob**2)) + ")")
+
+
+def cos_num(prob):
+    return "cos(" + str(generate_expression(prob**2)) + ")"
+
+
+def sin_num(prob):
+    return "sin(" + str(generate_expression(prob**2)) + ")"
+
+
+def cube_num(prob):
+    return "cube(" + str(generate_expression(prob**2)) + ")"
+
+
+def generate_expression(prob=0.99):
+    if random.random() < prob:
+        return random.choice([sin_pi(prob), cos_pi(prob),
+                              sin_num(prob), avg_num(prob),
+                              omg_wtf(prob)])
+    else:
+        return random.choice(['x', 'y'])
+
+
 def create_expression():
     """This function takes no arguments and returns an expression that
     generates a number between -1.0 and 1.0, given x and y coordinates."""
-    expr = lambda x, y: (random.random() * 2) - 1
+    expr = generate_expression()
     return expr
 
 
 def run_expression(expr, x, y):
     """This function takes an expression created by create_expression and
     an x and y value. It runs the expression, passing the x and y values
     to it and returns a value between -1.0 and 1.0."""
-    return expr(x, y)
+    return eval(expr)