[Tutor] Newbie problems

[Kirby Urner]

>
>Second, I don't know if this was already been posted but
>I want to make a simple "text menu" in order to choose
>what functions/sub-programs shall be executed.  My problem
>is, how will I "ignore" the wrong type of choices?  Please
>consider my simple text menu below:
>
>- - - < s n i p > - - -
>
>- MY SIMPLE PROGRAM -
>
>[1] Sub-program 1
>[2] Sub-program 2
>[3] Sub-program 3
>[4] Sub-program 4
>[5] Sub-program 5
>[Q/q] Exit
>
>Please enter your choice:

Here's a simple menu template based on the above.

def mainmenu():
         switch = [f1,f2,f3,f4,f5]
         while 1:
           print """

- MY SIMPLE PROGRAM -

[1] Sub-program 1
[2] Sub-program 2
[3] Sub-program 3
[4] Sub-program 4
[5] Sub-program 5
[Q/q] Exit

"""
           userselect = raw_input("Your selection?: ")
           if userselect.upper()=="Q":
              break  #escape from loop
            else:
              try:
                  menuchoice = int(userselect)-1
              except:  # doesn't convert to integer
                  print "Please select 1-5 or Q/q
                  continue  # loop from top
          if not menuchoice>4 and not menuchoice<0:
                switch[menuchoice]()  # valid index, execute
          else:
               print "Please select 1-5 or Q/q" # out of range

If it doesn't work, please check indentation -- cut and
pasted from IDLE.

Note:  use of raw_input to get string, conversion to
integer but trapping error if it doesn't convert.

The "subprograms" (non-Python terminology) are all
top-level functions, and must already be defined for the
above to work.  I've used simple stub functions:

def f1(): print "Menu option 1"
def f2(): print "Menu option 2"
def f3(): print "Menu option 3"
def f4(): print "Menu option 4"
def f5(): print "Menu option 5"

Since Python doesn't have a switch statement, I've
initialized an array ('switch') and filled it with
pointers to (names of) these function objects.

A user selection which passes the convert-to-integer
and not-too-big-and-not-too-small tests gets to
serve as an index to this array.  But the user choice
was decremented by 1, as arrays are 0-indexed.

As these are callable function-objects, simply sticking
() after the selection (e.g. f1) causes execution thereof.

>Last but not the least, what is "gotoxy" of Pascal in Python?

Sorry, never heard of it.  Trying to position stuff on
screen?

Kirby

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