[Tutor] one line code

C Smith smichr at hotmail.com
Tue Apr 5 07:45:08 CEST 2005

> From: "Alan Gauld" <alan.gauld at freenet.co.uk>
>> With other words I'd like to tell Python: Convert into a float if
>> possible, otherwise append anyway.
> [ (type(x) == type(5) and float(x) or x) for x in mylist ]

This is a perfect opportunity to give the reminder that the conversion 
functions are also types that can be used more transparently for such 
type tests:

 >>> type(int)
<type 'type'>
 >>> type(1)==int
 >>> type(1)==float

If you really want a float and not an int then you should use the 
following 1-liner as suggested by the programming FAQ 1.2.11 ( 
http://www.python.org/doc/faq/programming.html ):

[ (type(x) == int and [float(x)] or [x])[0] for x in mylist]

 >>> l=['foo', 0]
 >>> [(type(x)==int and float(x) or x) for x in l]
['foo', 0]
 >>> # notice that 0 is still an int, not a float
 >>> [(type(x)==int and [float(x)] or [x])[0] for x in l]
['foo', 0.0]
 >>> # ok, that's better


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