[Tutor] trouble with "if"

[Adam Urbas]

ok well, I'm testing to see if the CC thing worked.

On 5/29/07, Adam Urbas <jped.aru at gmail.com> wrote:
> I'll try the CC thing.
>
> On 5/29/07, Adam Urbas <jped.aru at gmail.com> wrote:
> > Well, Brian, I am now very sure that we have different versions of
> > gmail, because on both the Quick Reply and the full reply screens,
> > there are no Reply buttons, or downpointing arrows.
> >
> > On 5/29/07, Adam Urbas <jped.aru at gmail.com> wrote:
> > > What is the actual command to exit the program.  I tried exit, which
> > > turned purple, so I know that does something.
> > >
> > > On 5/29/07, Adam Urbas <jped.aru at gmail.com> wrote:
> > > > No I don't think that worked either, because now it has a problem with
> > > > print.
> > > >
> > > > Please help.
> > > >
> > > > Au
> > > >
> > > > On 5/29/07, Adam Urbas <jped.aru at gmail.com> wrote:
> > > > > I'm having trouble with the parentheses after the def thing().  IDLE
> > > > > says that there is something wrong with it.  If I type something
> > > > > between them, it says that there is something wrong with the
> quotation
> > > > > marks.  If I just leave it like (), then it says that something is
> > > > > wrong with what is after the parentheses.  Unless my code is
> supposed
> > > > > to go between the parentheses.  I'll try that.
> > > > >
> > > > > On 5/29/07, Adam Urbas <jped.aru at gmail.com> wrote:
> > > > > > In the def welcome(), what do you put in the parentheses?  Another
> > > > > > question, what code do you use for ending the program.  I want the
> > > > > > user to be able to cancel the program from the main menu, where it
> > > > > > asks you to choose circle, square, etc.  Or even perhaps allow the
> > > > > > user to go back to a previous menu, well I suppose that would be
> the
> > > > > > def thing() code.  But what if they were at the part where the
> > program
> > > > > > was asking them to input the radius, how would I give them the
> > option
> > > > > > of returning to the list of given measurements of a circle?
> > > > > >
> > > > > > On 5/29/07, Brian van den Broek <broek at cc.umanitoba.ca> wrote:
> > > > > > > adam urbas said unto the world upon 05/29/2007 12:39 PM:
> > > > > > > > The scary part is, I think I understand this.  I copied your
> > last
> > > > > > > > example and put it in IDLE and it doesn't like you code.
> Never
> > > > > > > > mind.  I figured it out.  So that is so it will notify you if
> > your
> > > > > > > > choice is invalid.  Nice lil tidbit of information there.
> I'll
> > be
> > > > > > > > sure to use this.  Oh and while your here, I'd like to ask
> about
> > > > > > > > loops I guess they are.  I want to have the program go back to
> > the
> > > > > > > > part where it asks for the user to select an option after it
> has
> > > > > > > > run one of its if statements.Like, when the user tells it,
> > > > > > > > "circle," then "radius," then enters the radius: here I would
> > like
> > > > > > > > the program to go back and ask the user if they want to do
> > > anything
> > > > > > > > else, like find the area of a square, instead of the circle.
> > > Would
> > > > > > > > I have to tell python to print all those selections again, or
> > > would
> > > > > > > > there be a way to just return to the beginning?Thanks,Au>
> Date:
> > > > > > >
> > > > > > >
> > > > > > > Hi Adam,
> > > > > > >
> > > > > > > Again, I cut the mess, but I expect that if you use the gmail
> > > account
> > > > > > > you just posted about here on in, that will be the end of it.
> > > > > > >
> > > > > > > I'm glad that you are starting to have the warm glow of
> > > understanding
> > > > > :-)
> > > > > > >
> > > > > > > What you are asking about here is one reason why functions are
> so
> > > > > > > useful. They allow you (more or less) to give a name to a chunk
> of
> > > > > > > code, and then you can rerun that chunk at will by invoking the
> > > name.
> > > > > > >
> > > > > > > Given the problem you want to solve, I'd structure my code
> > something
> > > > > > > like the following. Most of the details need to be filled in,
> but
> > > this
> > > > > > > is the skeletal structure.
> > > > > > >
> > > > > > >
> > > > > > > def welcome_message():
> > > > > > >      # Some actions to invoke when the user starts the program
> > > > > > >      print "Welcome to this program."
> > > > > > >
> > > > > > > def display_menu():
> > > > > > >      # Insert code for showing the user the menu of options
> > > > > > >      pass
> > > > > > >
> > > > > > > def circle_area():
> > > > > > >      # insert code here to ask user for the radius, compute the
> > > area,
> > > > > > >      # and display the result. You might well want to divide
> that
> > up
> > > > > > >      # into other functions that this one calls.
> > > > > > >      pass
> > > > > > >
> > > > > > > def square_area():
> > > > > > >      # Likewise
> > > > > > >      pass
> > > > > > >
> > > > > > > # And so on, for each shape that you wish to handle
> > > > > > >
> > > > > > > def exit_message():
> > > > > > >      # Some actions to invoke when the user chooses to terminate
> > > > > > >      # the program.
> > > > > > >      print "Thank you for using this program. Goodbye."
> > > > > > >
> > > > > > > def prompt_user():
> > > > > > >      # Here is where the sort of code I showed you before would
> > go.
> > > > > > >      # I'd include an option, say 0, for exiting, which, when
> the
> > > > > > >      # user picks it, you call exit_message()
> > > > > > >
> > > > > > >      while True:
> > > > > > >          try:
> > > > > > >              choice = int(raw_input("Please make your choice "))
> > > > > > >              if choice < 0 or choice > 2: # Adjust to suit
> options
> > > > > > >                  raise ValueError
> > > > > > >              break
> > > > > > >          except ValueError:
> > > > > > >              print "Please make a choice from the options
> > offered."
> > > > > > >
> > > > > > >      # sends the choice back to the code that called prompt_user
> > > > > > >      # We won't get here until a good choice has been made
> > > > > > >      return choice
> > > > > > >
> > > > > > > def main():
> > > > > > >      # The main function driving your program. It might look
> > > > > > >      # something like this:
> > > > > > >      welcome_message()
> > > > > > >
> > > > > > >      while True:   # This will loop forever until you break out
> > > > > > >          display_menu()
> > > > > > >          choice = prompt_user()
> > > > > > >
> > > > > > >          if choice == 0:
> > > > > > >              exit_message()
> > > > > > >              break   # Terminate the while loop
> > > > > > >          elif choice == 1:  # Assuming 1 was the option for
> circle
> > > > > > >              circle_area()
> > > > > > >          elif choice == 2:
> > > > > > >              square_area()
> > > > > > >          # And so on
> > > > > > >
> > > > > > >          print "Please make another choice:"   # Go back to top
> of
> > > > loop
> > > > > > >
> > > > > > >
> > > > > > > if __name__ == '__main__':
> > > > > > >      # This will run if you run the script, but not if you
> import
> > > it.
> > > > > > >      main()
> > > > > > >
> > > > > > >
> > > > > > > This has not been tested (it is only an outline) but it does
> pass
> > > the
> > > > > > > only so reliable eyeball check :-)
> > > > > > >
> > > > > > > I'd suggest you try filling this sketch out to be useful, and
> post
> > > if
> > > > > > > you run into troubles.
> > > > > > >
> > > > > > > Best,
> > > > > > >
> > > > > > > Brian vdB
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>