How to generate "a, b, c, and d"?

[Tim Chase]

On 12/15/11 12:19, Ethan Furman wrote:
> Tim Chase wrote:
>> On 12/15/11 10:48, Roy Smith wrote:
>>> I've got a list, ['a', 'b', 'c', 'd'].  I want to generate the string,
>>> "a, b, c, and d" (I'll settle for no comma after 'c').  Is there some
>>> standard way to do this, handling all the special cases?
>>
>> If you have a list, it's pretty easy as MRAB suggests.  For arbitrary
>> iterators, it's a bit more complex.  Especially with the odd edge-case
>> of 2 items where there's no comma before the conjunction (where>2 has
>> the comma before the conjunction).  If you were willing to forgo the
>> Oxford comma, it would tidy up the code a bit.
>
> Why go through all that instead of just converting the iterator into a
> list at the beginning of MRAB's solution and then running with it?

For the fun/challenge?  Because you have a REALLY big data source 
that you don't want to keep in memory (in addition the resulting 
string)?

Yeah, for most non-pathological cases, it would make more sense 
to just make it a list and then deal with the 4 cases (no 
elements, one element, 2 elements, and >2 elements) individually.

-tkc