Hi Paul,
Also consider the section in the PEP format "How would we teach this?" How would you explain to someone with no programming background, maybe a high school student, that 3/4 and 3 / 4 mean different things in Python? Your audience might not even know that there is a difference between "fraction", "decimal" and "float" at this stage.
Well, I think a high school student would be the one with the least problems: s/he would just realize "wow, that thing can do fractions! I can do my math homework with that!" And I can tell you, kids will be the first ones to figure out that if you type spaces you get decimals, if you do not type spaces you get fractions. They are used to this kind of stuff from their math class, from calculators (or their phones, I guess). So, if you show them (the following is fake) >>> 1/2 + 1/3 5/6 >>>> 1 / 2 + 1 / 3 0.833333 They will immediately spot what's going on.