variable creation

[Alistair King]

Hei all,

im trying to create a list of variables for further use:


Els = raw_input("Are there any further elements you would like to 
include? if so type the element, eg, Pd. If not type No: ")

    if Els != 'No':
        el = Els in pt
        while el == 1 and Els != 'Next':
            elements = []
            elements.insert(-1, Els)

            Els = raw_input("Which further element would you like to 
include, eg, Pd, if not type Next: ")
            el = Els in pt
           
            while el == 0 and Els != 'Next':
                Els = raw_input("This is not an element in the periodic 
table, please try again, eg Pd, If you dont wish to include any more, 
type Next: ")
                if el == 1:
                    elements.insert(-1, Els)
                          
        while el == 0:
            Els = raw_input("This is not an element in the periodic 
table, please try again, eg Pd. If you dont wish to include any more, 
type Next: ")

    print elements


this works to a certain extent but gets stuck on some loop. Im a 
beginner and am not sure where im going wrong.

here is a portion of the dictionary containing typical elements:

pt = {'H': 1.00794, 'He': 4.002602, 'Li': 6.941, 'Be': 9.012182, 'B': 
10.811}


Ali


-- 
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 50429, Mobile +358 (0)50 5279446
Fax +358 9 191 50366