[Python-Dev] datetime nanosecond support (original) (raw)

Vincenzo Ampolo vincenzo.ampolo at gmail.com
Wed Jul 25 02:58:34 CEST 2012

Hi all,

This is the first time I write to this list so thank you for considering this message (if you will) :)

I know that this has been debated many times but until now there was no a real use case. If you look on google about "python datetime nanosecond" you can find more than 141k answer about that. They all say that "you can't due to hardware imprecisions" or "you don't need it" even if there is a good amount of people looking for this feature.

But let me explain my use case:

most OSes let users capture network packets (using tools like tcpdump or wireshark) and store them using file formats like pcap or pcap-ng. These formats include a timestamp for each of the captured packets, and this timestamp usually has nanosecond precision. The reason is that on gigabit and 10 gigabit networks the frame rate is so high that microsecond precision is not enough to tell two frames apart. pcap (and now pcap-ng) are extremely popular file formats, with millions of files stored around the world. Support for nanoseconds in datetime would make it possible to properly parse these files inside python to compute precise statistics, for example network delays or round trip times.

More about this issue at http://bugs.python.org/issue15443

I completely agree with the YAGNI principle that seems to have driven decisions in this area until now but It is the case to reconsider it since this real use case has shown up?

Thank you for your attention

Best Regards,

Vincenzo Ampolo http://vincenzo-ampolo.net http://goshawknest.wordpress.com

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