getPageSource is not working for RSelenium - parsing

My goal is to retrieve information about the reviews which are located on different pages. I created a csv file with URL for every page and set each row as a destination for navigation of remotedriver. I created a loop for Selenium which was supposed to visit all this urls and retrieve needed nodes. After that
I created a loop for retrieving html page nodes and making unified dataframe out of this (via combining the result of each iteration in the loop with df with the same names of columns - was created before).
Actually i did this two month ago but now I am able to get only page source for the first page but not the next. At the same time the remotedriver is navigating the pages smoothly (it means URLs are alright!)
Example of the code:
uuu<-read.csv("/Users/uuu.csv")
data<-data.frame(title=character(),
date_travel=character(),
grades=character())
####starting selenium####
rd<-rsDriver(remoteServerAddr = "localhost", browser = "firefox", port=9353L)
for (i in 1:nrow(uuu)){
tryCatch({
url<-uuu$url[i]
cd<-rd$client
cd$navigate(url)
Sys.sleep(2)
reviews2<-read_html(cd$getPageSource()[[1]])
title<-reviews2 %>%
html_nodes(".ocfR3SKN") %>%
html_text()
date_travel<-reviews2 %>%
html_nodes("._34Xs-BQm") %>%
html_text()
try(
{
record_url<-data.frame(title,
date_travel))
}
, silent = T
)
try(
{
data <- bind_rows(data, record_url)
}
, silent = T
)
Sys.sleep(2)
})
}
The result of the parsing - seems like that he managed to get only the page source of the first urlbut not the others. However RD was navigating them.`

Related

YouTube API - retrieve more than 5k items

I just want to fetch all my liked videos ~25k items. as far as my research goes this is not possible via the YouTube v3 API.
I have already found multiple issues (issue, issue) on the same problem, though some claim to have fixed it, but it only works for them as they don't have < 5000 items in their liked video list.
playlistItems list API endpoint with playlist id set to "liked videos" (LL) has a limit of 5000.
videos list API endpoint has a limit of 1000.
Unfortunately those endpoints don't provide me with parameters that I could use to paginate the requests myself (e.g. give me all the liked videos between date x and y), so I'm forced to take the provided order (which I can't get past 5k entries).
Is there any possibility I can fetch all my likes via the API?
more thoughts to the reply from #Yarin_007
if there are deleted videos in the timeline they appear as "Liked https://...url" , the script doesnt like that format and fails as the underlying elements dont have the same structure as existing videos
can be easily fixed with a try catch
function collector(all_cards) {
var liked_videos = {};
all_cards.forEach(card => {
try {
// ignore Dislikes
if (card.innerText.split("\n")[1].startsWith("Liked")) {
....
}
}
catch {
console.log("error, prolly deleted video")
}
})
return liked_videos;
}
to scroll down to the bottom of the page ive used this simple script, no need to spin up something big
var millisecondsToWait = 1000;
setInterval(function() {
window.scrollTo(0, document.body.scrollHeight);
console.log("scrolling")
}, millisecondsToWait);
when more ppl want to retrive this kind of data, one could think about building a proper script that is more convenient to use. If you check the network requests you can find the desired data in the response of requests called batchexecute. One could copy the authentification of one of them provide them to a script that queries those endpoints and prepares the data like the other script i currently manually inject.
Hmm. perhaps Google Takeout?
I have verified the youtube data contains a csv called "liked videos.csv". The header is Video Id,Time Added, and the rows are
dQw4w9WgXcQ,2022-12-18 23:42:19 UTC
prvXCuEA1lw,2022-12-24 13:22:13 UTC
for example.
So you would need to retrieve video metadata per video ID. Not too bad though.
Note: the export could take a while, especially with 25k videos. (select only YouTube data)
I also had an idea that involves scraping the actual liked videos page (which would save you 25k HTTP Requests). But I'm unsure if it breaks with more than 5000 songs. (also, emulating the POST requests on that page may prove quite difficult, albeit not impossible. (they fetch /browse?key=..., and have some kind of obfuscated / encrypted base64 strings in the request-body, among other parameters)
EDIT:
Look. There's probably a normal way to get a complete dump of all you google data. (i mean, other than takeout. Email them? idk.)
anyway, the following is the other idea...
Follow this deep link to your liked videos history.
Scroll to the bottom... maybe with selenium, maybe with autoit, maybe put something on the "end" key of your keyboard until you reach your first liked video.
Hit f12 and run this in the developer console
// https://www.youtube.com/watch?v=eZPXmCIQW5M
// https://myactivity.google.com/page?utm_source=my-activity&hl=en&page=youtube_likes
// go over all "cards" in the activity webpage. (after scrolling down to the absolute bottom of it)
// create a dictionary - the key is the Video ID, the value is a list of the video's properties
function collector(all_cards) {
var liked_videos = {};
all_cards.forEach(card => {
// ignore Dislikes
if (card.innerText.split("\n")[1].startsWith("Liked")) {
// horrible parsing. your mileage may vary. I Tried to avoid using any gibberish class names.
let a_links = card.querySelectorAll("a")
let details = a_links[0];
let url = details.href.split("?v=")[1]
let video_length = a_links[3].innerText;
let time = a_links[2].parentElement.innerText.split(" • ")[0];
let title = details.innerText;
let date = card.closest("[data-date]").getAttribute("data-date")
liked_videos[url] = [title,video_length, date, time];
// console.log(title, video_length, date, time, url);
}
})
return liked_videos;
}
// https://stackoverflow.com/questions/57709550/how-to-download-text-from-javascript-variable-on-all-browsers
function download(filename, text, type = "text/plain") {
// Create an invisible A element
const a = document.createElement("a");
a.style.display = "none";
document.body.appendChild(a);
// Set the HREF to a Blob representation of the data to be downloaded
a.href = window.URL.createObjectURL(
new Blob([text], { type })
);
// Use download attribute to set set desired file name
a.setAttribute("download", filename);
// Trigger the download by simulating click
a.click();
// Cleanup
window.URL.revokeObjectURL(a.href);
document.body.removeChild(a);
}
function main() {
// gather relevant elements
var all_cards = document.querySelectorAll("div[aria-label='Card showing an activity from YouTube']")
var liked_videos = collector(all_cards)
// download json
download("liked_videos.json", JSON.stringify(liked_videos))
}
main()
Basically it gathers all the liked videos' details and creates a key: video_ID - Value: [title,video_length, date, time] object for each liked video.
It then automatically downloads the json as a file.

How do I reset the ScanStreamTransformer Accumulator?

I am writing a Flutter application using the BLOC pattern. I'm currently trying to search a database and return a list of results on the screen.
The first search will complete fine. The issue is when I hit the back button and try to do a second search. The first search results aren't cleared out. Instead they remain on the screen and the new search results are placed below them.
In a nutshell here's what I'm doing.(I'm using the RxDart library)
1.) Defining input and output streams:
PublishSubject<SearchRowModel> _searchFetcher =
PublishSubject<BibSearchRowModel>();
BehaviorSubject<Map<int, SearchRowModel>> _searchOutput =
BehaviorSubject<Map<int, SearchRowModel>>();
2.) Piping the streams together in the class constructor.
_searchFetcher.stream.transform(_resultsTransformer()).pipe(_searchOutput);
3.) Adding the results to the fetcher stream
results.searchRows.forEach((SearchRowModel row) {
_searchFetcher.sink.add(row);
});
4.) Using a ScanStreamTransformer to create a map of the results.
_resultsTransformer() {
return ScanStreamTransformer(
(Map<int, SearchRowModel> cache, SearchRowModel row, index) {
cache[index] = row;
return cache;
},
<int, SearchRowModel>{},
);
}
From my debugging, I've found that the code in step 4 appears to be the issue. That cache (or the Accumulator) isn't getting reset between searches. It just keeps adding additional results to the map.
I've yet to find a way of resetting the map in the accumulator / cache that works. I even tried completely destroying the streams and recreating them, but the original search data in the SearchstreamTransformer accumulator still persisted.

BigQueryIO loads not offloading rows to GCS when early trigger occurs

I'm playing around with BigQueryIO write using loads. My load trigger is set to 18 hours. I'm ingesting data from Kafka with a fixed daily window.
Based on https://github.com/apache/beam/blob/v2.2.0/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BatchLoads.java#L213-L231 it seems that the intended behavior is to offload rows to the filesystem when at least 500k records are in a pane
I managed to produce ~ 600K records and waited for around 2 hours to see if the rows were uploaded to gcs, however, nothing was there. I noticed that the "GroupByDestination" step in "BatchLoads" shows 0 under "Output collections" size.
When I use a smaller load trigger all seems fine. Shouldn't the AfterPane.elementCountAtLeast(FILE_TRIGGERING_RECORD_COUNT)))) be triggered?
Here is the code for writing to BigQuery
BigQueryIO
.writeTableRows()
.to(new SerializableFunction[ValueInSingleWindow[TableRow], TableDestination]() {
override def apply(input: ValueInSingleWindow[TableRow]): TableDestination = {
val startWindow = input.getWindow.asInstanceOf[IntervalWindow].start()
val dayPartition = DateTimeFormat.forPattern("yyyyMMdd").withZone(DateTimeZone.UTC).print(startWindow)
new TableDestination("myproject_id:mydataset_id.table$" + dayPartition, null)
}
})
.withMethod(Method.FILE_LOADS)
.withCreateDisposition(CreateDisposition.CREATE_NEVER)
.withWriteDisposition(WriteDisposition.WRITE_APPEND)
.withSchema(BigQueryUtils.schemaOf[MySchema])
.withTriggeringFrequency(Duration.standardHours(18))
.withNumFileShards(10)
The job id is 2018-02-16_14_34_54-7547662103968451637. Thanks in advance.
Panes are per key per window, and BigQueryIO.write() with dynamic destinations uses the destination as key under the hood, so the "500k elements in pane" thing applies per destination per window.

How to implement pagination when using amazon Dynamo DB in rails

I want to use amazon Dynamo DB with rails.But I have not found a way to implement pagination.
I will use AWS::Record::HashModel as ORM.
This ORM supports limits like this:
People.limit(10).each {|person| ... }
But I could not figured out how to implement following MySql query in Dynamo DB.
SELECT *
FROM `People`
LIMIT 1 , 30
You issue queries using LIMIT. If the subset returned does not contain the full table, a LastEvaluatedKey value is returned. You use this value as the ExclusiveStartKey in the next query. And so on...
From the DynamoDB Developer Guide.
You can provide 'page-size' in you query to set the result set size.
The response of DynamoDB contains 'LastEvaluatedKey' which will indicate the last key as per the page size. If response does't contain 'LastEvaluatedKey' it means there are no results left to fetch.
Use the 'LastEvaluatedKey' as 'ExclusiveStartKey' while fetching next time.
I hope this helps.
DynamoDB Pagination
Here's a simple copy-paste-run proof of concept (Node.js) for stateless forward/reverse navigation with dynamodb. In summary; each response includes the navigation history, allowing user to explicitly and consistently request either the next or previous page (while next/prev params exist):
GET /accounts -> first page
GET /accounts?next=A3r0ijKJ8 -> next page
GET /accounts?prev=R4tY69kUI -> previous page
Considerations:
If your ids are large and/or users might do a lot of navigation, then the potential size of the next/prev params might become too large.
Yes you do have to store the entire reverse path - if you only store the previous page marker (per some other answers) you will only be able to go back one page.
It won't handle changing pageSize midway, consider baking pageSize into the next/prev value.
base64 encode the next/prev values, and you could also encrypt.
Scans are inefficient, while this suited my current requirement it won't suit all!
// demo.js
const mockTable = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
const getPagedItems = (pageSize = 5, cursor = {}) => {
// Parse cursor
const keys = cursor.next || cursor.prev || [] // fwd first
let key = keys[keys.length-1] || null // eg ddb's PK
// Mock query (mimic dynamodb response)
const Items = mockTable.slice(parseInt(key) || 0, pageSize+key)
const LastEvaluatedKey = Items[Items.length-1] < mockTable.length
? Items[Items.length-1] : null
// Build response
const res = {items:Items}
if (keys.length > 0) // add reverse nav keys (if any)
res.prev = keys.slice(0, keys.length-1)
if (LastEvaluatedKey) // add forward nav keys (if any)
res.next = [...keys, LastEvaluatedKey]
return res
}
// Run test ------------------------------------
const runTest = () => {
const PAGE_SIZE = 6
let x = {}, i = 0
// Page to end
while (i == 0 || x.next) {
x = getPagedItems(PAGE_SIZE, {next:x.next})
console.log(`Page ${++i}: `, x.items)
}
// Page back to start
while (x.prev) {
x = getPagedItems(PAGE_SIZE, {prev:x.prev})
console.log(`Page ${--i}: `, x.items)
}
}
runTest()
I faced a similar problem.
The generic pagination approach is, use "start index" or "start page" and the "page length". 
The "ExclusiveStartKey" and "LastEvaluatedKey" based approach is very DynamoDB specific.
I feel this DynamoDB specific implementation of pagination should be hidden from the API client/UI.
Also in case, the application is serverless, using service like Lambda, it will be not be possible to maintain the state on the server. The other side is the client implementation will become very complex.
I came with a different approach, which I think is generic ( and not specific to DynamoDB)
When the API client specifies the start index, fetch all the keys from
the table and store it into an array.
Find out the key for the start index from the array, which is
specified by the client.
Make use of the ExclusiveStartKey and fetch the number of records, as
specified in the page length.
If the start index parameter is not present, the above steps are not
needed, we don't need to specify the ExclusiveStartKey in the scan
operation.
This solution has some drawbacks -
We will need to fetch all the keys when the user needs pagination with
start index.
We will need additional memory to store the Ids and the indexes.
Additional database scan operations ( one or multiple to fetch the
keys )
But I feel this will be very easy approach for the clients, which are using our APIs. The backward scan will work seamlessly. If the user wants to see "nth" page, this will be possible.
In fact I faced the same problem and I noticed that LastEvaluatedKey and ExclusiveStartKey are not working well especially when using Scan So I solved Like this.
GET/?page_no=1&page_size=10 =====> first page
response will contain count of records and first 10 records
retry and increase number of page until all record come.
Code is below
PS: I am using python
first_index = ((page_no-1)*page_size)
second_index = (page_no*page_size)
if (second_index > len(response['Items'])):
second_index = len(response['Items'])
return {
'statusCode': 200,
'count': response['Count'],
'response': response['Items'][first_index:second_index]
}

Where can I find a large tabbed hierarchical data set for parser testing?

First, apologies as I realize this is only tangentially related to parser programming.
I've spend hours looking for a text file containing something like the following but with hundreds (hopefully thousands) of sub-entries. A complete biological classification file would be perfect. A massive version of the following would be great as my parser parses simple tabbed files:
TL,DR - I need a massive single-file hierarchical data set something like the following:
Kindoms
Monera
Protista
Fungi
Plants
Animals
Porifera
Sponges
Coelenterates
Hydra
Coral
Jellyfish
Platyhelminthes
Flatworms
Flukes
Nematodes
Roundworms
Tapeworms
Chordates
Urochordataes
Cephalochordates
Vertebrates
Fish
Amphibians
Reptiles
Birds
Mammals
The best I've been able to find are tree-of-life images (from which I transcribed the sample data set above). A single file with a TON of real data would be awesome. It doesn't have to be a biological classification data set, but I would really like the data to reflect something in the real-world. (My parser feeds a menu - would be great if the remainder of my testing was with a data set that actually meant something!) Even if the file is not tabbed but the data was fairly easily regex'ed to a tabbed format... that would be great.
Any ideas? Thanks!
It is possible that the xml layout was changed since the last answer but the code submitted above is no longer accurate. The resulting dump is extraneous. Some of the nodes have aliases (denoted as 'othername') that are reported as distinct nodes themselves.
I used the script below to generate the correct dump.
<?php
$reader = new XMLReader();
$reader->open('http://tolweb.org/onlinecontributors/app?service=external&page=xml/TreeStructureService&node_id=1'); //15963 is the primates index
$set=-1;
while ($reader->read()) {
switch ($reader->nodeType) {
case (XMLREADER::ELEMENT):
if ($reader->name == "OTHERNAMES"){
$set=1;
}
if ($reader->name == "NODES"){
$set=-1;
}
if ($reader->name == "NODE"){
$set=-1;
}
if ($reader->name == "NAME" AND $set == -1){
echo str_repeat("\t", $reader->depth - 2); //repeat tabs for depth
$node = $reader->expand();
echo $node->textContent . "\n";
}
break;
}
}
?>
This turned out to be such a pain in the ass. I finally tracked down a data feed from "The Tree of Life Web Project" at tolweb.org. I made the php script below to provide the basic functionality my post was looking for.
Change the node_id to have it print a tabbed representation of any of tolweb.org's data - just take the id from the page you're browsing on their site and change the node_id below.
Be aware though - their data feeds serve up large files, so definitely download the file to your own server (and change the "open" method below to point to the local file) if you're going to hit it more than once or twice.
More info on tolweb.org data feeds can be found here:
http://tolweb.org/tree/home.pages/downloadtree.html
<?php
$reader = new XMLReader();
$reader->open('http://tolweb.org/onlinecontributors/app?service=external&page=xml/TreeStructureService&node_id=15963'); //15963 is the primates index
while ($reader->read()) {
switch ($reader->nodeType) {
case (XMLREADER::ELEMENT):
if ($reader->name == "NAME"){
echo str_repeat("\t", $reader->depth - 2); //repeat tabs for depth
$node = $reader->expand();
echo $node->textContent . "\n";
}
break;
}
}
?>

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