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Firestore can not write date as collection name

I'm trying to write to Firestore all the prices from different stocks. Structure should look something like this (although this might not be the best fitted for it, still thinking of it as in SQL) :
const d1 = new Date();
const result = d1.getTime();
console.log('Epochtime',result);
database.collection("stock1").doc("exchange1").collection(date).doc('prices').set({"price":"price_value"})
Now the problem is that I can't create a collection with a name that's a variable that contains date. I tried all the different types of it and I presumed that epoch time should work, as this is a number like: 1636213439908. I always get the error: Value for argument "collectionPath" is not a valid resource path. Path must be a non-empty string. Although the exact same variable can be written as a value in a collection. So not sure what am I doing wrong here.

Document IDs in Firestore must be strings, so you'll have to convert the data to a string. While date.toString() will work, I highly recommend using a ISO-8601 format for the dates, such as date.toISOString(). These formats are designed to be both humanly readable and machine sortable.

How can I keep only 100 latest entries in CSV file per group

I have an application where I need to measure timestamp based parameter values from each device. The information is heavily structured and the reason I haven't looked into databases is because I have to get all the data for 100 x 1000 = 100k rows every few minutes. I want to delete the data corresponding to the oldest timestamp in each group. I am using Python for programming but even JavaScript would do. I could not find the limit parameter in the Python CSV official module. Help is super appreciated.
Item 1
Timestamp, parameter1, parameter2...parameterN
...
100 rows
Item 2
Timestamp, parameter1, parameter2...parameterN
...
100 rows
...1000 items
Note: There are no headers to separate any rows, the Item 1,2 etc. are shown for representational purposes.
I need to be able to add new row every few minutes under each group and get rid of the old one effectively keeping the numbers at 100 per group

There's no limit parameter, because a reader is just an iterator, and Python has generic ways to do anything you might want to do with any iterator.
with open(path) as f:
r = csv.reader(f)
First 100:
itertools.islice(r, 100)
Last 100:
collections.deque(r, maxlen=100)
Max 100 by 3rd column:
heapq.nlargest(100, r, key=operator.itemgetter(2))
… and so on.

Store your data internally like this
dict [key] [timestamp][array of values]
data={}
if 'bob' in data:
data['bob']={}
data['bob'][timestamp]=list(values)
else:
data['bob'][new_timestamp]=list(values)
After 2 iterations your data array will look like
data['bob'][15000021][1,2,3,4,5]
data['bob'][15003621][5,6,7,8,9,0]
If you want the latest ... just get the unique keys for bob - and delete
- either anything more than n items (bob's values sorted by timestamp)
- or if the timestamp is less than now() - 2 days [or whatever your rule]
I use both mechanisms in similar datasets. I strongly suggest you then save this data, in case your process exists.
Should your data contain an OrderedDictionary (which would make the removal easier) - please not pickle will fail, however the excellent module dill (I am not kidding) is excellent, and handles all datatypes and closes much nicer IMHO.

** Moving from Comments **
I'm assuming reading the file from the bottom up help you... This can be done by prepending entries to the beginning of the file.
With that assumption you just need to rewrite the file on each entry. Read the new file to an array, push() the new entry, shift() the list and write to new file.
Alternatively you can continue to push() to the file and only read the first 100 entries. After doing your read you can remove the file and start a new one if you expect to consistently get more than 100 entries between reads, or you can clean the file to just 100 entries

csv to multi-dimensional array

I'm far from good at javascript. I'm cobbling together a page to analyze a csv file and created a page with results.
So I'm using papaparse.js for csv parsing and the stepFn to process each line, to eliminate records using various selection criteria.
I've also included moment.js to handle dates and times.
so there's 3 pieces of data I want to work with. (I'm simplifying).
[fundraising] team, amount, and date (which I'll store as a unix time integer).
I've been trying to see if outdata[teamname] exists, and if it does, update the amount. And if the amount >= goalamount, then populate date (if it's not already populated).
basically my web page allows them to define selection criteria, a goal, and to choose whether the challenge was [who gets their first]/sort on date, or [who got the most] sort on amount. [where total can actually be a count or
if the team isn't in the outdata array, add it, and place in it the total and a date (which of course I have to check for goal-reaching).
I've tried
var exists = typeof outdata[thisteamname];
if (exists == undefined)
{
outdata.push({ team: thisteamname, total: usevalue, adate: 0 });
}
else
{
var z = outdata[thisteamname]['total'];
//---->>> Cannot read property 'total' of undefined
outdata[thisteamname]['total'] += usevalue;
}
etc .. but i think I'm going about it all wrong. Suggestions? I will also need to sort the outdata array by eithe date or total, and loop through it for a top-ten style list at the end to write html.
all help appreciated, I know my javascript looks rather BASICy.

Importing data from a javascript table(?) to excel

I'm trying to import data For a large number of dates from here: https://demanda.ree.es/movil/peninsula/demanda/tablas/2014-11-03/2
Once/if that's possible I want to automate it so it retrieves the data for a given set of dates. Say, entire 2013.
I can't find anything in the webpage source that would give a hint as to from where the data is retrieved from. I've tried importing the data both using:
Data/From Web: Gets javascript error
Open/ Other web locations: Just retrieves a worksheet filled with grey cells, no data.
Thanks for any help!

Use the following links:
https://demanda.ree.es/WSvisionaMovilesPeninsulaRest/resources/maxMinPeninsula?callback=angular.callbacks._0&curva=DEMANDA&fecha=2013-01-01
https://demanda.ree.es/WSvisionaMovilesPeninsulaRest/resources/prevProgPeninsula?callback=angular.callbacks._1&curva=DEMANDA&fecha=2013-01-01
https://demanda.ree.es/WSvisionaMovilesPeninsulaRest/resources/demandaGeneracionPeninsula?callback=angular.callbacks._2&curva=DEMANDA&fecha=2013-01-01
https://demanda.ree.es/WSvisionaMovilesPeninsulaRest/resources/coeficientesCO2?callback=angular.callbacks._3&curva=DEMANDA&fecha=2013-01-01
Use the "fecha" parameter to set the date. It seems it is not possible to get the whole year at once so you should iterate the calls to that link and change "fecha" to 2013-01-02, 2013-01-03, etc. for each month.

Muchas gracias #miguel-febres! It now works more or less*. Where did you find the links from? :)
It runs some 10-20 loops and returns an address error, upon which I just start the macro again and it works... strange.
Sub Macro1()
Application.DisplayAlerts = False
Do
Workbooks.OpenText Filename:="https://demanda.ree.es/WSvisionaMovilesPeninsulaRest/resources/demandaGeneracionPeninsula?callback=angular.callbacks._2&curva=DEMANDA&fecha=" & ActiveCell.Value & ""
Range(Selection, Selection.End(xlToRight)).Select
Selection.Copy
Windows("Spain").Activate
ActiveCell.Offset(1, 0).Range("A1").Select
Selection.PasteSpecial Paste:=xlPasteAll, Operation:=xlNone, SkipBlanks:= _
False, Transpose:=True
'close table
Windows("demandaGeneracionPeninsula").Activate
ActiveWindow.Close
ActiveCell.Offset(-1, 1).Activate
Loop Until ActiveCell.Value = ""
End Sub
Now I just have to parse the results.. :)

javascript: array of object for simple localization

I need to implement a simple way to handle localization about weekdays' names, and I came up with the following structure:
var weekdaysLegend=new Array(
{'it-it':'Lunedì', 'en-us':'Monday'},
{'it-it':'Martedì', 'en-us':'Tuesday'},
{'it-it':'Mercoledì', 'en-us':'Wednesday'},
{'it-it':'Giovedì', 'en-us':'Thursday'},
{'it-it':'Venerdì', 'en-us':'Friday'},
{'it-it':'Sabato', 'en-us':'Saturday'},
{'it-it':'Domenica', 'en-us':'Sunday'}
);
I know I could implement something like an associative array (given the fact that I know that javascript does not provide associative arrays but objects with similar structure), but i need to iterate through the array using numeric indexes instead of labels.
So, I would like to handle this in a for cycle with particular values (like j-1 or indexes like that).
Is my structure correct? Provided a variable "lang" as one of the value between "it-it" or "en-us", I tried to print weekdaysLegend[j-1][lang] (or weekdaysLegend[j-1].lang, I think I tried everything!) but the results is [object Object]. Obviously I'm missing something..
Any idea?

The structure looks fine. You should be able to access values by:
weekdaysLegend[0]["en-us"]; // returns Monday
Of course this will also work for values in variables such as:
weekdaysLegend[i][lang];
for (var i = 0; i < weekdaysLegend.length; i++) {
alert(weekdaysLegend[i]["en-us"]);
}
This will alert the days of the week.
Sounds like you're doing everything correctly and the structure works for me as well.

Just a small note (I see the answer is already marked) as I am currently designing on a large application where I want to put locals into a javascript array.
Assumption: 1000 words x4 languages generates 'xx-xx' + the word itself...
Thats 1000 rows pr. language + the same 7 chars used for language alone = wasted bandwitdh...
the client/browser will have to PARSE THEM ALL before it can do any lookup in the arrays at all.
here is my approach:
Why not generate the javascript for one language at a time, if the user selects another language, just respond(send) the right javascript to the browser to include?
Either store a separate javascript with large array for each language OR use the language as parametre to the server-side script aka:
If the language file changes a lot or you need to minimize it per user/module, then its quite archivable with this approach as you can just add an extra parametre for "which part/module" to generate or a timestamp so the cache of the javascript file will work until changes occures.
if the dynamic approach is too performance heavy for the webserver, then publish/generate the files everytime there is a change/added a new locale - all you'll need is the "language linker" check in the top of the page, to check which language file to server the browser.
Conclusion
This approach will remove the overhead of a LOT of repeating "language" ID's if the locales list grows large.

You have to access an index from the array, and then a value by specifying a key from the object.
This works just fine for me: http://jsfiddle.net/98Sda/.
var day = 2;
var lang = 'en-us';
var weekdaysLegend = [
{'it-it':'Lunedì', 'en-us':'Monday'},
{'it-it':'Martedì', 'en-us':'Tuesday'},
{'it-it':'Mercoledì', 'en-us':'Wednesday'},
{'it-it':'Giovedì', 'en-us':'Thursday'},
{'it-it':'Venerdì', 'en-us':'Friday'},
{'it-it':'Sabato', 'en-us':'Saturday'},
{'it-it':'Domenica', 'en-us':'Sunday'}
];
alert(weekdaysLegend[day][lang]);