Usage

Using this package is relatively straightforward. There are two common paths that people take directly, and one common path when deserializing data.

Named usage

First, if you are interactively looking to use or get information about an isotope, you can simply import it. This package lazily creates only those isotopes you actually use, and it uses a singlton approach to limit the memory footprint, so you should feel safe in importing any isotope you need.

from isotopes import U235, U238
assert U235.Z == U238.Z
assert U238.A > U235.A
assert U238.abundance > U235.abundance

Z-A-m definition and ZAID promotion

If you want to create an isotope not by strict naming but by its ZAID, you can do so either through direct creation, or by promoting a ZAID. Promoting a ZAID gives you a fallback option for when data for your isotope is missing and we can only give you a ZAID object instead:

from isotopes import ZAID, Isotope, U235

iso1 = Isotope(92, 235, 0)
assert iso1 is U235
iso2 = Isotope.from_zaid_with_fallback(ZAID(92, 235, 0))
assert iso2 is iso1 is U235

Integer promotion

Sometimes, you already have a ZAID as its integer number. This is often the case when you’re deserialzing isotopes from some ascii or binary format. In this case, you have an integer on your hand, which you want to promote back to an Isotope, if possible, or a ZAID, if not. In that case:

from isotopes import ZAID, Isotope, U235

i = int(U235)
iso = Isotope.from_int_with_fallback(i)
assert iso is U235