Validate user input

[ennoil]

I am requesting user input from a menu a script. The input I am requesting needs to be an integer. Is it possible to validate that the user actually entered an integer and not a string or just hit enter? Everything I have tried will give me
"File "<string>", line 0, in ?
NameError: name 'd' is not defined
The code I have looks like this:

def init_menu():
  print '''
  0) Exit
  1) Environment
  2) Use
  3) OS
  4) Arch
  5) ALL
  6) Done
  '''
  ROW = input("Choose your server type: [0]")
#  ROW = ROW.strip()
  print
#  if len(ROW) == 0:
#    print 'Exiting...'
#    sys.exit(0)
  if ROW == 0:
    sys.exit(0)
  elif ROW == 1:
    print 'You have chosen by', INITIAL.get(ROW)
  elif ROW == 2:
    print 'You have chosen by', INITIAL.get(ROW)
  elif ROW == 3:
    print 'You have chosen by', INITIAL.get(ROW)
  elif ROW == 4:
    print 'You have chosen by', INITIAL.get(ROW)
  elif ROW == 5:
    print 'You have chosen', INITIAL.get(ROW)
  elif ROW == 6:
    print 'You are', INITIAL.get(ROW)
  else:
    sys.exit(0)
  return ROW

The print statements for each choice are just place holders and will have actual actions associated with them eventually

Thanks,
John

[BeatSlayer]

Something like this maybe, I'm just a beginner so maybe theres a better option.

row = 0
 
while int(row) not in range(1,8):
    row = raw_input('''
        0) Exit
        1) Environment
        2) Use
        3) OS
        4) Arch
        5) ALL
        6) Done
    : ''')
 
row = int(row)

[ennoil]

That does look better than my code but still errors if the user does not enter a number (or, more importantly for this) just hits enter.

[dwblas]

isdigit() will work fine for this. Note that it returns False for a float.

test_strs = [ "12345", " 0123", "123.45", \
              "-123", "123x5", "12*67", " 12 45"]
for eachstr in test_strs :
    print "%7s" % eachstr,
 
    if eachstr.isdigit( ) :
        print " IS",
    else :
        print " is NOT",
    print "a digit" 

[Glenton]

In this case you want to do a bunch of tests, so I would invert the logic:

while True:
    row = raw_input('''
        0) Exit
        1) Environment
        2) Use
        3) OS
        4) Arch
        5) ALL
        6) Done
    : ''')
    if row="": continue
    if isdigit(row) and row in range(1,7): break

Of course the if row="": continue bit isn't necessary, but I just include it in case you need the idea for something else.

Also, the "and" operator is a short-cut operator, meaning that the second part is only evaluated when the first part is True. Handy that, or you'd get an error...