Running python on unix

[kpatrick1979]

Hi, 

I am a brand new user learning python for a programming languages
class.  I am trying to use the practice tutorial to mimic the
following if-statement exercise:

>>> x = int(raw_input("Please enter an integer: "))
>>> if x < 0:
...      x = 0
...      print 'Negative changed to zero'
... elif x == 0:
...      print 'Zero'
... elif x == 1:
...      print 'Single'
... else:
...      print 'More'
...

However, after I enter the first line of code (i'm using the Python
command line programming that you can get from the web) I immediately
get the "Please enter an integer" line -- it doesn't permit me to type
the rest of the code.  Does anyone know a better way for me to try and
do this program?  I tried using Unix, but am not having much success
there either (maybe i'm doing that wrong too)  Help!

Thanks,
K