List of strings to list of floats ?

[Madhusudan Singh]

skip at pobox.com wrote:

> 
>     Madhusudan> Is it possible to convert a very long list of strings to a
>     Madhusudan> list of floats in a single statement ?
> 
>     Madhusudan> I have tried float(x) and float(x[:]) but neither work. I
>     Madhusudan> guess I would have to write a loop if there isn't a way.
> 
> Try:
> 
>     >>> los = ["123.0", "2", "1e-6"]
>     >>> map(float, los)
>     [123.0, 2.0, 9.9999999999999995e-07]
>     >>> [float(s) for s in los]
>     [123.0, 2.0, 9.9999999999999995e-07]
> 
> Skip

Thanks. Now, a slightly more complicated question.

Say I have two lists of floats. And I wish to generate a list of floats that
is a user defined function of the two lists.

I tried :

def rpyth(x,y):
    r=sqrt(pow(x,2.0)+pow(y,2.0))
    return r

r1n=map(rpyth,x2n[1:len(x2n)-1],y2n[1:len(y2n)-1])

And I get an error complaining about floats.