Le 14/07/2014 22:53, Tim Peters a écrit :
>
> That consumes exactly 10 bytes today. Add nanoseconds, and it will
take at least 11 (if 4 bits are insanely squashed into the bytes
currently devoted to microseconds), and more likely 12 (if nanoseconds
are sanely given their own 2 bytes).

That doesn't have to be. For example you could use the MSB of the 
microseconds field to store a "datetime pickle flags" byte, which could 
tell the unserializer whether a nanoseconds (or attoseconds :-)) field 
follows or not.

Remember that existing pickles must remain readable, so there must be 
some kind of version field anyway.