dict problem

[Alistair King]

Ben Finney wrote:
> Alistair King <alistair.king at helsinki.fi> writes:
>
>   
>> Ben Finney wrote:
>>     
>>> Even better, work on a minimal program to do nothing but reproduce
>>> the unexpected behaviour. If you get to such a program and still
>>> don't understand, then post it here so others can run it
>>> themselves and explain.
>>>       
>> ive checked the values and XDS is actually returning a string where i
>> want a float ie '123.45' not 123.45.
>>     
>
> Can you please post a small, complete program that shows the behaviour
> you want explained?
>
> You get this program by writing it -- either by cutting away
> irrelevant parts of the existing program, or (better) writing a new
> program from scratch that does nothing except demonstrate the
> behaviour.
>
> Note that in the process of getting such a program behaving this way,
> you may end up understanding the problem better.
>
>   
i have seemed to work out most of the problems from the previous code,
now i have:
...................................................................................................................................................

heavy = raw_input("\n\n@@@@@@@@@@@@@@@@@@\n\nPlease enter the heaviest
atom for which you obtained percentage values for, but not Oxygen, eg,
'C', 'N', 'S', 'Br'...: ")

print DSvalues

def updateDS1v(Fxas, x):
if Fxas != 0:
value = DSvalues.get(heavy)
floatvalue = float(value)
atoms = DS1v.get(x) + Fxas*floatvalue
DS1v[x] = atoms

updateDS1v(FCas, 'C')

print DS1v
...................................................................................................................................................

the problem now is converting badly formatted dictionary values into floats
ive been trying something like this, where 'value' is a typical entry
into the dictionary:
...................................................................................................................................................

IDLE 1.1
>>> value = "'0.064250000000001084'"
>>> print float(value)

and get the error, in IDLE and the code as:

Traceback (most recent call last):
File "<pyshell#3>", line 1, in -toplevel-
print float(value)
ValueError: invalid literal for float(): '0.064250000000001084'

...................................................................................................................................................

Is there any other way of removing double and single quotes from a
number, as a string, to give the float value again?

I know it would be easier to create a properly formatted dictionary
again and i will do that but it would be good to know as i want to get
this program running properly to get some results i need for work.
Everything else seems to be working fine but this.

thanks

a

-- 
Dr. Alistair King
Research Chemist,
Laboratory of Organic Chemistry,
Department of Chemistry,
Faculty of Science
P.O. Box 55 (A.I. Virtasen aukio 1)
FIN-00014 University of Helsinki
Tel. +358 9 191 50392, Mobile +358 (0)50 5279446
Fax +358 9 191 50366