Clarification: timestamp on datafeed return unclear value

Jacob

I'm trying to understand a certain value of datetime that I can't understand.

step by step:

loading a .csv file with custom GenericCSVData.
datetime is in timestamp format, so 'params' will have 'dtformat' set to 1 (int timestamp format)
adding a simple strategy that on 'next' will try to print the timestamp value

the timestamp I used in the data: 1364636880 (which correlate to '30 March 2013 09:48:00')
if I do 'print((self.datas[0].datetime)[0])' I get: 734957.9999999999
and if I do ''print(self.datas[0].datetime.date(0))' I get: 2013-03-30

my clarification question is just to understand what is the value '(self.datas[0].datetime)[0]' represents? (734957.9999999999)

backtrader

@jacob said in Clarification: timestamp on datafeed return unclear value:

the timestamp I used in the data: 1364636880 (which correlate to '30 March 2013 09:48:00')
if I do 'print((self.datas[0].datetime)[0])' I get: 734957.9999999999
and if I do ''print(self.datas[0].datetime.date(0))' I get: 2013-03-30

Your input date is the 30th of March of 2013 and the output is in isoformat 2013-03-30.

Were you expecting anything else?

@jacob said in Clarification: timestamp on datafeed return unclear value:

my clarification question is just to understand what is the value '(self.datas[0].datetime)[0]' represents? (734957.9999999999)

It's the timestamp coded inside a float.

Jacob

was just wondering if I could easily make sense of the date format.
was expecting the unix style timestamp

I'm focusing now on learning the library and although a lot of things are very intuitive.
some things I can't see while debugging which leave a gap in my understanding.

I will give an example of what i mean:
if while debugging I 'watch' self.datas[0] I don't see in the object hierarchy having '.datetime' yet alone find it also have .date() function.

this leave me with a concern that i will not be able to fully use the system cause i can't see everything.
(found the above code in the docs but i doubt i could have found it myself)

I switched now to use pycharm (instead of VS) but still can't see attributes like '.datetime'
but it did help me find the num2date() function that convert the float number to a normal date

backtrader

@jacob said in Clarification: timestamp on datafeed return unclear value:

was expecting the unix style timestamp

From Wikipedia - Unix time:

Unix time (also known as POSIX time[citation needed] or UNIX Epoch time[1]) is a system for describing a point in time, defined as the number of seconds

It would be difficult to express anything in the sub-second realm with the Unix timestamp.

@jacob said in Clarification: timestamp on datafeed return unclear value:

if while debugging I 'watch' self.datas[0] I don't see in the object hierarchy having '.datetime' yet alone find it also have .date() function.

I believe in this case the trees don't let you see the forest. If something is not found in a lines object itself, it will be sought in the defined lines. And datetime is one of the defined lines for an OHLC timeseries.

You probably want to read this: Docs - Platform Concepts and specifically the section (and its subsections) Lines

Jacob

Thanks @backtrader for the explanation