Python timestamps with time()

Question

I have a few timestamps in a database that I would like to trim down to only about 10 timestamps, from most latest to oldest. All the timestamps in the DB were made using time() in python.

Create timestamp:

_timestamp = time.time()

Timestamps:

1435652632.92778
1435652633.01
1435652633.07
1435652633.13
1435652642.71371
1435652642.77
1435652675.13
1435652675.22
1435652717.74
1435652735.11
1435652735.16
1435652735.24

How can I ask python to remove the oldest timestamp?

I currently convert the timestamp to readable format using the below string in my script.

print datetime.datetime.fromtimestamp(1434615010.27858)
>>2015-06-18 08:10:10.278580

I have no code yet to remove the oldest timestamps, however I would appreciate some help with this please.

What kind of database is it? You can almost certainly ask the *database* to remove rows outside the top 10. See [Delete all but top n from database table in SQL](http://stackoverflow.com/q/46385) — Martijn Pieters, Jul 08 '15 at 12:59
The timestamps are all in one column of a row, separated by "-". — Dusty Boshoff, Jul 08 '15 at 13:00
So they are all in a string? Then just split, convert to floats, sort and keep only the 10 highest. Or even use `heapq.nlargest()` if you want to do it with the most efficient method available. — Martijn Pieters, Jul 08 '15 at 13:01
`datetime.datetime()` objects are also sortable, so if you already have them converted like that just sort, take the first 10, etc. — Martijn Pieters, Jul 08 '15 at 13:03

Arturs Vancans · Accepted Answer · 2015-07-09T08:57:06.457

4

This is an epoch timestamp which is simply seconds passed since 1970-01-01T00:00:00Z.

In you case, sort the timestmaps and take the 10 top elements.

timestmaps = [1435652632.92778, 1435652633.01, 1435652633.07]
timestmaps.sort(reverse=True)
latestTimestamps = timestmaps[:10]

edited Jul 09 '15 at 08:57

answered Jul 08 '15 at 13:02

Arturs Vancans

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@MartijnPieters touché :) – Arturs Vancans Jul 08 '15 at 13:06
You should use `reverse=True`, to keep the latest timestamps. Is there any reason not to use `heapq.nlargest(10, timestamps)` here? – jfs Jul 09 '15 at 00:23

score 0 · Answer 2 · answered Jul 08 '15 at 13:06

Not sure if it's what you want, but you can do this:

timestamps = [1435652632.92778,1435652633.01,1435652633.07,1435652633.13,1435652642.71371,1435652642.77,1435652675.13,1435652675.22,1435652717.74,1435652735.11,1435652735.16,1435652735.24]
timestamps.remove(min(timestamps)) #Remove the minimum value from the list

Python timestamps with time()

2 Answers2