Hi VvS ,
I would do it using a regular expression. It's a little more cumbersome, but can handle things like there being a single letter for the element symbol and one, two or three digits for the mass. I'm sure there are other ways of doing it too, but here's an example:
import re
list = ['Li7','Mg25','Al27','Si29','S34','Sr88','Y89','U238','Measurement','Time','ID']
ch_re = r'([A-Z]{1}[a-z]{0,1})(\d{1,3})'
for item in list:
match = re.split(ch_re, item)
if len(match) > 1:
symbol = match[1]
mass = match[2]
print(symbol)
print(mass)
Please let me know how it goes.
-Bence
