# File: except6a.py
# Program to read in a positive number
# and complain when the input isn't that
# uses a global to convey error occurred
#
# Matt Bishop, MHI 289I, Winter 2018

# True if error encountered when something read;
# False otherwise
err = False

# read in a positive number
#
def getposnumber():
    global err
    
    # read the input and convert it to an integer
    # notice we do *not* catch the error here; it
    # is to be caught by the caller
    try:
        n = int(raw_input("type a number: "))
    except ValueError:
        print "ValueError in getposnumber()"
        n = 0
        err = True

    # now just return it
    return n

#
# the program itself
#
def main():
    global err
    #
    # loop to show exception handling
    #    
    while True:

        # read in a positive integer
        # handle any exceptions (relatively) intelligently
        try:
            err = False
            n = getposnumber()
        # exception: bad value (string, invalid number)
        except ValueError as msg:
            print msg, "-- try again!"             # give it another chance
        # exception: end of file
        except EOFError as msg:
            print msg, "-- bye!"                   # quit
            break
        # some other exception
        except:
            print "Unknown exception -- ignoring!" # ignore the problem
        # no exception -- print the number
        else:
            if err == True:
                pass
            elif n <= 0:
                print "You typed a non-positive number"
            else:
                print "Read", n
        finally:
            print "\n-----------------------\n"

main()