def getInt(small,large):
    prompt = 'Enter a number from %d to %d: ' % (small,large)
    errorMsg = 'Your number must be between %d and %d.' % (small,large)
    number = small-1                      # intentionally invalid
    while not small <= number <= large:
      try:
        number = int(raw_input(prompt))
        if not small <= number <= large:
          print errorMsg
      except ValueError:
        print 'That is not a valid integer.'
    return number

(click to see it run live)

def sliding(word, num=3):
    if not isinstance(word,str):
        raise TypeError('first parameter must be a string')
    if not isinstance(num,int):
        raise TypeError('second parameter must be an integer')
    if not 0 < num <= len(word):
        raise ValueError('second parameter can be at most length of first')

def toDecimal(string, base):
    if not isinstance(base, int):
        raise TypeError('base must be integral')
    if not 2 <= base <= 36:
        raise ValueError('base must be between 2 and 36')
    if not isinstance(string, str):
        raise TypeError('value must be expressed as a string')
    for digit in string:
	if digit.isdigit():
	    if not 0 <= int(digit) < base:
                raise ValueError('invalid digit for given base')
	else
	    val = 10 + ord(digit) - ord('A')
	    if not 10 <= val < base:
                raise ValueError('invalid digit for given base')

def getInt(small,large):
    if not (isinstance(small,int) and isinstance(large,int)):
        raise TypeError('parameters must be integer')
    if not small < large:
        raise ValueError('large must be bigger than small')
    ...