# ShowForStrings.py
"""  Illustrates the use of for-loops
in problems where it is necessary to
traverse a string."""


def Reverse(s):
    """ Returns a string that is obtained
    from s by reversing the order of its characters.
    
    Precondition: s is a string."""
    t =''
    for c in s:
        t = c+t
    return t
    
def nDigits(s):
    """ Returns an int whose value is the number
    of digit characters that are in s.
    Precondition: s is a string."""
    n = 0;
    for c in s:
        # Increment n if c is a digit
        if c.isdigit():
            n=n+1
    return n

if __name__ == '__main__':
    print 'Using raw_input so enter strings without  the apostrophe delimiters.\n'
    x = raw_input('Enter a string to reverse: ')
    y = Reverse(x)
    print '              The reverse: %s' % y
    x = raw_input('Enter a string with some digits: ')
    m = nDigits(x)
    print '               Number of digits: %1d' %m