Get date format

[VladShyrokyi]

Hi,
I would like to be able to get the date format from a string. For example, one could add a getFormatPattern method to get a format string that can be used further for business logic.
My case:
I am doing a csv parser, I need to be able to define the data type in a column, this library could help me if it had this function.

[sisyphsu]

It's possible, dateparser could detect the format of a date string, internally.

But, the format detected is regex, is it what you want?

[VladShyrokyi]

Not really, need a standard according to https://www.w3.org/TR/NOTE-datetime. So that format can be reused with other libraries, possibly in other languages. For example, when the back end processes a csv document, it sends the converted data with format information that the front end processes with their libraries.

[VladShyrokyi]

Example to use:

var date = "1994-11-05 13:15:30";
var dateFormat = DateParserUtils.parseFormat(date);
assert dateFormat = "YYYY-MM-DD hh:mm:ss";

var date = "1994-11-05";
var dateFormat = DateParserUtils.parseFormat(date);
assert dateFormat = "YYYY-MM-DD";

var date = "11-05-1994 13:15:30";
var dateFormat = DateParserUtils.parseFormat(date);
assert dateFormat = "DD-MM-YYYY hh:mm:ss";

var date = "11-05";
var dateFormat = DateParserUtils.parseFormat(date);
assert dateFormat = "DD-MM";

var date = "04 Jul 2021 19:59:09";
var dateFormat = DateParserUtils.parseFormat(date);
assert dateFormat = "DD MMM YYYY hh:mm:ss";

[sisyphsu]

There has too many formats supported in dateparser, I don't think it's a good idea to use it like this.

[primeap]

Hi @sisyphsu ,

lets say we have csv file .... we want to format a date column .... we can improve performance if we know date format

so can we get date format

thanks

[akash-yadagouda]

I was about to start implementing the code to get the date format given the date string.

Then I stopped because there are some test cases which are making trouble.

1. 11/11/2022
   Is it in DD/MM/YYYY format or MM/DD/YYYY?

Its better to have or follow the date/time format in a project where we are defining these.

[VladShyrokyi]

You can declare precedence for formats.

When somebody passes one string to the method, you check a list of formats by precedence.
If need to find a format for the string list need create another method for this case. Although, format check logic can be reused.