Extracting float from string

[Don Arnold]

Spencer Ernest Doidge <spencer at efn.org> wrote in message news:<avvp7s$l1i$1 at news.efn.org>...
> From a previous post,
> I got many good solutions to extracting an int from
> 'X= 445 A'.
> 
> Now what about this one?
> Somewhere (we don't know where) in this input string, we expect to find a float:
> ':X=  0.22456  A'
> 
> How can I suck the float out of this one?

This isn't all that pretty, but appears to work:

str = ':X=  0.22456  A 423 12.345 a.b'
for item in [x for x in str.split()]:
    try:
        float(item)
        if item.find('.') != -1:
            print '%s is a float' % item
        else:
            print '%s is not a float but can be converted to one' % item
    except:
        print '%s is not a float' % item
        
>>> 
:X= is not a float
0.22456 is a float
A is not a float
423 is not a float but can be converted to one
12.345 is a float
a.b is not a float

>>> 


HTH,
Don