Alex's .py

Hi, I'm Alex. I created this Python blog to show people the latest games and code I'm working on, along with explanations and examples for anyone looking to learn more about Python, CGI / server-side programming, or just internet game development in general. Let me know what you think, and thanks for visiting!

Apr 10, 2013 : math_test.py

Here's a breakdown of how the math_test.py source code works, in 6 easy steps...

Interactive html games rely on recursion, which we accomplish in this example with two branches: a problem frame, and an evaluation frame.

Check if the program is being asked to execute a problem frame or an evaluation frame, by looking for a hidden CGI variable called "eval_frame"...

#!/usr/bin/python import cgi, cgitb cgitb.enable() form = cgi.FieldStorage() from time import time try: eval_frame = int(form.getvalue('eval_frame')) except: eval_frame = 0

If the current frame is a problem frame, then generate a random algebra problem and start the timer...

if eval_frame == 0: # generate ABCD, prompt user to solve for x import random x = random.randint(2,9)*((-1)**random.randint(0,1)) Q = random.randint(2,9)*((-1)**random.randint(0,1)) P = xQ A = random.randint(3,90) C = A - Q B = random.randint(2,18)((-1)**random.randint(0,1)) D = B + P time1 = time()

If the current frame is an evaluation frame, then check if the user's answer is correct and stop the timer...

else: try: user_answer = int(form.getvalue('user_answer')) except: user_answer = 0 A = int(form.getvalue('A')) B = int(form.getvalue('B')) C = int(form.getvalue('C')) D = int(form.getvalue('D')) time1 = float(form.getvalue('time1')) time2 = time() dt = int(1000(time2 - time1))/1000. if user_answer == (D-B)/(A-C): user_correct = 1 else: user_correct = 0

Print the algebra problem to the game GUI (user's html browser)...

str1 = str(A) + "x + " + str(B) + " = " + str(C) + "*x + " + str(D) print 'Content-type:text/html\r\n\r\n' print '<html><body>' print '<h2 style="font-family:courier; font-size:16px; text-align:left;">' print '<BR/>' print 'Test #1: Solve for x... ' print '<BR/><BR/>' print ' ' + str1 print '<BR/><BR/>'

If this is a problem frame, then display a box for the user to enter his/her answer into, along with other necessary game info as hidden variables...

if eval_frame == 0: print '<form action="/cgi-bin/math_test_bluehost.py" method="post">' print ' x = <input type="text" name="user_answer" size="3" maxlength="3">' print '<input type="hidden" name="A" value="' + str(A) + '" />' print '<input type="hidden" name="B" value="' + str(B) + '" />' print '<input type="hidden" name="C" value="' + str(C) + '" />' print '<input type="hidden" name="D" value="' + str(D) + '" />' print '<input type="hidden" name="time1" value="' + str(time1) + '" />' print '<input type="hidden" name="eval_frame" value="1" />' print '<input type="submit" value="Enter" /> </form>'

If this is an evaluation frame, then display whether the user's answer was right or wrong along with how long it took them to give their answer...

else: print '<form action="/cgi-bin/math_test_bluehost.py" method="post">' x = (D-B)/(A-C) if user_answer == x: print " Correct! The answer was x = " + str(x) + ". Time = " + str(dt) + " seconds." else: print " Wrong! The answer was x = " + str(x) print '<input type="hidden" name="eval_frame" value="0" />' print '<input type="submit" value="Try Again" /> </form>' print '</h2>' print '</body></html>'

Here's some other great python blogs I like to check out:

Nadia Alramli's Blog
The "Invent with Python" Blog
Carter Sande's Blog