[Tutor] Flip the coin 10x and count heads and tails: It works now!

[Ken G.]

On 05/25/2013 05:25 AM, Rafael Knuth wrote:
> Gents,
>
> thank you all for your help. One of you guys asked me to try out your
> suggestions and then tell you how it goes. Here we go! First, let me
> recap briefly what the expected outcome of my program was and which
> difficulties I encountered at the beginning. I was writing a program
> in Python 3.3.0 which flips a coin 10 x times and then counts the
> number of heads and tails. It obviously did something else than I
> intended:
>
> import random
>
> print ("""
>
> This program flips a coin 10 times.
> It then counts the number of heads and tails.
>
> """)
>
> flips = 0
> heads = 0
> tails = 0
>
> while flips < 10:
>      flips = flips + 1
>      if random.randint(1,2) == 1:
>          heads = heads + 1
>          print("We've got " + str(heads) + " heads here."
>      if random.randint(1,2) == 2:
>          tails = tails + 1
>          print("We've got " + str(tails) + " tails here.")
>
> This is what I got as output:
>
> This program flips a coin 10 times.
> It then counts the number of heads and tails.
>
> We've got 1 tails here.
> We've got 1 heads here.
> We've got 2 tails here.
> We've got 2 heads here.
> We've got 3 tails here.
> We've got 3 heads here.
> We've got 4 tails here.
> We've got 5 tails here.
> We've got 4 heads here.
> We've got 6 tails here.
> We've got 7 tails here.
> We've got 5 heads here.
>
> As it turned out, each of your answers was *partially* correct, so I
> played around with your suggestions until I got my code up and
> running. Frankly, I did two mistakes: First, I placed the print
> statement inside the loop instead of outside of it. And second, I
> mistakenly called the random function two times inside the loop. In
> order to resolve that issue, I had to modify the heads and tails
> variables and then add another variable and put it inside the loop:
>
> result = random.randint(1,2)
>
> Lastly, I figured out that counting the results can be done in a more
> elegant fashion. Instead of:
>
> variable_XYZ = variable_XYZ + 1
>
> … it can be done this way:
>
> variable_XYZ += 1
>
> I got so excited when I saw my program run properly that I decided to
> pimp it a little bit by printing each head and tail with a time delay
> while the coin got flipped during the run. Here’s what my code looks
> like now:
>
> import random
> import time
>
> print ("""
>
> This program flips a coin 10 times.
> It then counts the number of heads and tails.
>
> """)
> time.sleep(1)
>
> flips = 0
> heads = 0
> tails = 0
>
> while flips < 10:
>      result = random.randint(1,2)
>      if result == 1:
>          heads += 1
>          print("head")
>          time.sleep(1)
>      elif result == 2:
>          tails += 1
>          print("tail")
>          time.sleep(1)
>      flips += 1
> print ("\nYou've got " + str(heads) + " heads and " + str(tails) + " tails.")
>
> I have one last question to you: I explained twice in my initial mail
> what I expect my program to do (“I am writing a program in Python
> 3.3.0 which flips a coin 10 x times and then counts the number of
> heads and tails.”). I did that the introduction as well as inside my
> code. However, almost each of you asked me what I expect my program to
> do. I was confused about that and I am wondering if any of you can
> clarify? I just want to make sure I avoid misunderstandings like these
> in the future.
>
> Thank you all again!
>
> All the best,
>
>
>
> Rafael
May I suggest that instead of:

flips = 0
heads = 0
tails = 0

how about:

flips = heads = tails = 0

Ken