hello, its me again :-)

[Julius Welby]

Just for fun, this one handles multi digit input and catches divide by zero.
It looks like it could be made much shorter by iterating through a list of
operators.

(If nothing else, you may want to use string.lower in your script to get rid
of the 'X' versus 'x' distiction)
#######

import string
e = raw_input('Enter expression --> ')
e = string.lower(e)
ans = 'Invalid Operator'

try:
    sp = string.split(e, '*')
    ans = float(sp[0]) * float(sp[1])
except:
    pass

try:
    sp = string.split(e, 'x')
    ans = float(sp[0]) * float(sp[1])
except:
    pass

try:
    sp = string.split(e, '/')
    if float(sp[1]) == 0:
        ans = "Divide by zero error!"
    else:
        ans = float(sp[0]) / float(sp[1])
except:
    pass

try:
    sp = string.split(e, '+')
    ans = float(sp[0]) + float(sp[1])
except:
    pass

try:
    sp = string.split(e, '-')
    ans = float(sp[0]) - float(sp[1])
except:
    pass

print ans