- [Does the issue involve one problem, and one problem only?](#does-the-issue-involve-one-problem-and-one-problem-only)
- [Is anyone going to need the feature?](#is-anyone-going-to-need-the-feature)
- [Is your question about yt-dlp?](#is-your-question-about-yt-dlp)
+ - [Are you willing to share account details if needed?](#are-you-willing-to-share-account-details-if-needed)
+ - [Is the website primarily used for piracy](#is-the-website-primarily-used-for-piracy)
- [DEVELOPER INSTRUCTIONS](#developer-instructions)
- [Adding new feature or making overarching changes](#adding-new-feature-or-making-overarching-changes)
- [Adding support for a new site](#adding-support-for-a-new-site)
- [Provide fallbacks](#provide-fallbacks)
- [Regular expressions](#regular-expressions)
- [Long lines policy](#long-lines-policy)
+ - [Quotes](#quotes)
- [Inline values](#inline-values)
- [Collapse fallbacks](#collapse-fallbacks)
- [Trailing parentheses](#trailing-parentheses)
- [Use convenience conversion and parsing functions](#use-convenience-conversion-and-parsing-functions)
+ - [My pull request is labeled pending-fixes](#my-pull-request-is-labeled-pending-fixes)
- [EMBEDDING YT-DLP](README.md#embedding-yt-dlp)
Bugs and suggestions should be reported at: [yt-dlp/yt-dlp/issues](https://github.com/yt-dlp/yt-dlp/issues). Unless you were prompted to or there is another pertinent reason (e.g. GitHub fails to accept the bug report), please do not send bug reports via personal email. For discussions, join us in our [discord server](https://discord.gg/H5MNcFW63r).
-**Please include the full output of yt-dlp when run with `-Uv`**, i.e. **add** `-Uv` flag to **your command line**, copy the **whole** output and post it in the issue body wrapped in \`\`\` for better formatting. It should look similar to this:
+**Please include the full output of yt-dlp when run with `-vU`**, i.e. **add** `-vU` flag to **your command line**, copy the **whole** output and post it in the issue body wrapped in \`\`\` for better formatting. It should look similar to this:
```
-$ yt-dlp -Uv <your command line>
+$ yt-dlp -vU <your command line>
[debug] Command-line config: ['-v', 'demo.com']
[debug] Encodings: locale UTF-8, fs utf-8, out utf-8, pref UTF-8
[debug] yt-dlp version 2021.09.25 (zip)
If your report is shorter than two lines, it is almost certainly missing some of these, which makes it hard for us to respond to it. We're often too polite to close the issue outright, but the missing info makes misinterpretation likely. We often get frustrated by these issues, since the only possible way for us to move forward on them is to ask for clarification over and over.
-For bug reports, this means that your report should contain the **complete** output of yt-dlp when called with the `-Uv` flag. The error message you get for (most) bugs even says so, but you would not believe how many of our bug reports do not contain this information.
+For bug reports, this means that your report should contain the **complete** output of yt-dlp when called with the `-vU` flag. The error message you get for (most) bugs even says so, but you would not believe how many of our bug reports do not contain this information.
If the error is `ERROR: Unable to extract ...` and you cannot reproduce it from multiple countries, add `--write-pages` and upload the `.dump` files you get [somewhere](https://gist.github.com).
### Is the issue already documented?
-Make sure that someone has not already opened the issue you're trying to open. Search at the top of the window or browse the [GitHub Issues](https://github.com/yt-dlp/yt-dlp/search?type=Issues) of this repository. If there is an issue, feel free to write something along the lines of "This affects me as well, with version 2021.01.01. Here is some more information on the issue: ...". While some issues may be old, a new post into them often spurs rapid activity.
+Make sure that someone has not already opened the issue you're trying to open. Search at the top of the window or browse the [GitHub Issues](https://github.com/yt-dlp/yt-dlp/search?type=Issues) of this repository. If there is an issue, subscribe to it to be notified when there is any progress. Unless you have something useful to add to the conversation, please refrain from commenting.
Additionally, it is also helpful to see if the issue has already been documented in the [youtube-dl issue tracker](https://github.com/ytdl-org/youtube-dl/issues). If similar issues have already been reported in youtube-dl (but not in our issue tracker), links to them can be included in your issue report here.
### Is your question about yt-dlp?
-Some bug reports are completely unrelated to yt-dlp and relate to a different, or even the reporter's own, application. Please make sure that you are actually using yt-dlp. If you are using a UI for yt-dlp, report the bug to the maintainer of the actual application providing the UI. On the other hand, if your UI for yt-dlp fails in some way you believe is related to yt-dlp, by all means, go ahead and report the bug.
+Some bug reports are completely unrelated to yt-dlp and relate to a different, or even the reporter's own, application. Please make sure that you are actually using yt-dlp. If you are using a UI for yt-dlp, report the bug to the maintainer of the actual application providing the UI. In general, if you are unable to provide the verbose log, you should not be opening the issue here.
If the issue is with `youtube-dl` (the upstream fork of yt-dlp) and not with yt-dlp, the issue should be raised in the youtube-dl project.
+### Are you willing to share account details if needed?
+
+The maintainers and potential contributors of the project often do not have an account for the website you are asking support for. So any developer interested in solving your issue may ask you for account details. It is your personal discretion whether you are willing to share the account in order for the developer to try and solve your issue. However, if you are unwilling or unable to provide details, they obviously cannot work on the issue and it cannot be solved unless some developer who both has an account and is willing/able to contribute decides to solve it.
+
+By sharing an account with anyone, you agree to bear all risks associated with it. The maintainers and yt-dlp can't be held responsible for any misuse of the credentials.
+
+While these steps won't necessarily ensure that no misuse of the account takes place, these are still some good practices to follow.
+
+- Look for people with `Member` (maintainers of the project) or `Contributor` (people who have previously contributed code) tag on their messages.
+- Change the password before sharing the account to something random (use [this](https://passwordsgenerator.net/) if you don't have a random password generator).
+- Change the password after receiving the account back.
+
+### Is the website primarily used for piracy?
+
+We follow [youtube-dl's policy](https://github.com/ytdl-org/youtube-dl#can-you-add-support-for-this-anime-video-site-or-site-which-shows-current-movies-for-free) to not support services that is primarily used for infringing copyright. Additionally, it has been decided to not to support porn sites that specialize in fakes. We also cannot support any service that serves only [DRM protected content](https://en.wikipedia.org/wiki/Digital_rights_management).
+
# DEVELOPER INSTRUCTIONS
-Most users do not need to build yt-dlp and can [download the builds](https://github.com/yt-dlp/yt-dlp/releases) or get them via [the other installation methods](README.md#installation).
+Most users do not need to build yt-dlp and can [download the builds](https://github.com/yt-dlp/yt-dlp/releases), get them via [the other installation methods](README.md#installation) or directly run it using `python -m yt_dlp`.
-To run yt-dlp as a developer, you don't need to build anything either. Simply execute
+`yt-dlp` uses [`hatch`](<https://hatch.pypa.io>) as a project management tool.
+You can easily install it using [`pipx`](<https://pipx.pypa.io>) via `pipx install hatch`, or else via `pip` or your package manager of choice. Make sure you are using at least version `1.10.0`, otherwise some functionality might not work as expected.
- python -m yt_dlp
+If you plan on contributing to `yt-dlp`, best practice is to start by running the following command:
+
+```shell
+$ hatch run setup
+```
-To run the test, simply invoke your favorite test runner, or execute a test file directly; any of the following work:
+The above command will install a `pre-commit` hook so that required checks/fixes (linting, formatting) will run automatically before each commit. If any code needs to be linted or formatted, then the commit will be blocked and the necessary changes will be made; you should review all edits and re-commit the fixed version.
- python -m unittest discover
- python test/test_download.py
- nosetests
- pytest
+After this you can use `hatch shell` to enable a virtual environment that has `yt-dlp` and its development dependencies installed.
+
+In addition, the following script commands can be used to run simple tasks such as linting or testing (without having to run `hatch shell` first):
+* `hatch fmt`: Automatically fix linter violations and apply required code formatting changes
+ * See `hatch fmt --help` for more info
+* `hatch test`: Run extractor or core tests
+ * See `hatch test --help` for more info
See item 6 of [new extractor tutorial](#adding-support-for-a-new-site) for how to run extractor specific test cases.
+While it is strongly recommended to use `hatch` for yt-dlp development, if you are unable to do so, alternatively you can manually create a virtual environment and use the following commands:
+
+```shell
+# To only install development dependencies:
+$ python -m devscripts.install_deps --include dev
+
+# Or, for an editable install plus dev dependencies:
+$ python -m pip install -e ".[default,dev]"
+
+# To setup the pre-commit hook:
+$ pre-commit install
+
+# To be used in place of `hatch test`:
+$ python -m devscripts.run_tests
+
+# To be used in place of `hatch fmt`:
+$ ruff check --fix .
+$ autopep8 --in-place .
+
+# To only check code instead of applying fixes:
+$ ruff check .
+$ autopep8 --diff .
+```
+
If you want to create a build of yt-dlp yourself, you can follow the instructions [here](README.md#compile).
## Adding new feature or making overarching changes
-Before you start writing code for implementing a new feature, open an issue explaining your feature request and atleast one use case. This allows the maintainers to decide whether such a feature is desired for the project in the first place, and will provide an avenue to discuss some implementation details. If you open a pull request for a new feature without discussing with us first, do not be surprised when we ask for large changes to the code, or even reject it outright.
+Before you start writing code for implementing a new feature, open an issue explaining your feature request and at least one use case. This allows the maintainers to decide whether such a feature is desired for the project in the first place, and will provide an avenue to discuss some implementation details. If you open a pull request for a new feature without discussing with us first, do not be surprised when we ask for large changes to the code, or even reject it outright.
-The same applies for overarching changes to the architecture, documentation or code style
+The same applies for changes to the documentation, code style, or overarching changes to the architecture
## Adding support for a new site
-If you want to add support for a new site, first of all **make sure** this site is **not dedicated to [copyright infringement](https://www.github.com/ytdl-org/youtube-dl#can-you-add-support-for-this-anime-video-site-or-site-which-shows-current-movies-for-free)**. yt-dlp does **not support** such sites thus pull requests adding support for them **will be rejected**.
+If you want to add support for a new site, first of all **make sure** this site is **not dedicated to [copyright infringement](#is-the-website-primarily-used-for-piracy)**. yt-dlp does **not support** such sites thus pull requests adding support for them **will be rejected**.
After you have ensured this site is distributing its content legally, you can follow this quick list (assuming your service is called `yourextractor`):
1. [Fork this repository](https://github.com/yt-dlp/yt-dlp/fork)
1. Check out the source code with:
- git clone git@github.com:YOUR_GITHUB_USERNAME/yt-dlp.git
+ ```shell
+ $ git clone git@github.com:YOUR_GITHUB_USERNAME/yt-dlp.git
+ ```
1. Start a new git branch with
- cd yt-dlp
- git checkout -b yourextractor
+ ```shell
+ $ cd yt-dlp
+ $ git checkout -b yourextractor
+ ```
1. Start with this simple template and save it to `yt_dlp/extractor/yourextractor.py`:
```python
- # coding: utf-8
from .common import InfoExtractor
'url': 'https://yourextractor.com/watch/42',
'md5': 'TODO: md5 sum of the first 10241 bytes of the video file (use --test)',
'info_dict': {
+ # For videos, only the 'id' and 'ext' fields are required to RUN the test:
'id': '42',
'ext': 'mp4',
- 'title': 'Video title goes here',
- 'thumbnail': r're:^https?://.*\.jpg$',
- # TODO more properties, either as:
- # * A value
- # * MD5 checksum; start the string with md5:
- # * A regular expression; start the string with re:
- # * Any Python type (for example int or float)
+ # Then if the test run fails, it will output the missing/incorrect fields.
+ # Properties can be added as:
+ # * A value, e.g.
+ # 'title': 'Video title goes here',
+ # * MD5 checksum; start the string with 'md5:', e.g.
+ # 'description': 'md5:098f6bcd4621d373cade4e832627b4f6',
+ # * A regular expression; start the string with 're:', e.g.
+ # 'thumbnail': r're:^https?://.*\.jpg$',
+ # * A count of elements in a list; start the string with 'count:', e.g.
+ # 'tags': 'count:10',
+ # * Any Python type, e.g.
+ # 'view_count': int,
}
}]
# TODO more properties (see yt_dlp/extractor/common.py)
}
```
-1. Add an import in [`yt_dlp/extractor/extractors.py`](yt_dlp/extractor/extractors.py).
-1. Run `python test/test_download.py TestDownload.test_YourExtractor`. This *should fail* at first, but you can continually re-run it until you're done. If you decide to add more than one test, the tests will then be named `TestDownload.test_YourExtractor`, `TestDownload.test_YourExtractor_1`, `TestDownload.test_YourExtractor_2`, etc. Note that tests with `only_matching` key in test's dict are not counted in. You can also run all the tests in one go with `TestDownload.test_YourExtractor_all`
-1. Make sure you have atleast one test for your extractor. Even if all videos covered by the extractor are expected to be inaccessible for automated testing, tests should still be added with a `skip` parameter indicating why the purticular test is disabled from running.
-1. Have a look at [`yt_dlp/extractor/common.py`](yt_dlp/extractor/common.py) for possible helper methods and a [detailed description of what your extractor should and may return](yt_dlp/extractor/common.py#L91-L426). Add tests and code for as many as you want.
-1. Make sure your code follows [yt-dlp coding conventions](#yt-dlp-coding-conventions) and check the code with [flake8](https://flake8.pycqa.org/en/latest/index.html#quickstart):
+1. Add an import in [`yt_dlp/extractor/_extractors.py`](yt_dlp/extractor/_extractors.py). Note that the class name must end with `IE`. Also note that when adding a parenthesized import group, the last import in the group must have a trailing comma in order for this formatting to be respected by our code formatter.
+1. Run `hatch test YourExtractor`. This *may fail* at first, but you can continually re-run it until you're done. Upon failure, it will output the missing fields and/or correct values which you can copy. If you decide to add more than one test, the tests will then be named `YourExtractor`, `YourExtractor_1`, `YourExtractor_2`, etc. Note that tests with an `only_matching` key in the test's dict are not included in the count. You can also run all the tests in one go with `YourExtractor_all`
+1. Make sure you have at least one test for your extractor. Even if all videos covered by the extractor are expected to be inaccessible for automated testing, tests should still be added with a `skip` parameter indicating why the particular test is disabled from running.
+1. Have a look at [`yt_dlp/extractor/common.py`](yt_dlp/extractor/common.py) for possible helper methods and a [detailed description of what your extractor should and may return](yt_dlp/extractor/common.py#L119-L440). Add tests and code for as many as you want.
+1. Make sure your code follows [yt-dlp coding conventions](#yt-dlp-coding-conventions), passes [ruff](https://docs.astral.sh/ruff/tutorial/#getting-started) code checks and is properly formatted:
+
+ ```shell
+ $ hatch fmt --check
+ ```
- $ flake8 yt_dlp/extractor/yourextractor.py
+ You can use `hatch fmt` to automatically fix problems. Rules that the linter/formatter enforces should not be disabled with `# noqa` unless a maintainer requests it. The only exception allowed is for old/printf-style string formatting in GraphQL query templates (use `# noqa: UP031`).
-1. Make sure your code works under all [Python](https://www.python.org/) versions supported by yt-dlp, namely CPython and PyPy for Python 3.6 and above. Backward compatability is not required for even older versions of Python.
+1. Make sure your code works under all [Python](https://www.python.org/) versions supported by yt-dlp, namely CPython and PyPy for Python 3.8 and above. Backward compatibility is not required for even older versions of Python.
1. When the tests pass, [add](https://git-scm.com/docs/git-add) the new files, [commit](https://git-scm.com/docs/git-commit) them and [push](https://git-scm.com/docs/git-push) the result, like this:
- $ git add yt_dlp/extractor/extractors.py
- $ git add yt_dlp/extractor/yourextractor.py
- $ git commit -m '[yourextractor] Add extractor'
- $ git push origin yourextractor
+ ```shell
+ $ git add yt_dlp/extractor/_extractors.py
+ $ git add yt_dlp/extractor/yourextractor.py
+ $ git commit -m '[yourextractor] Add extractor'
+ $ git push origin yourextractor
+ ```
1. Finally, [create a pull request](https://help.github.com/articles/creating-a-pull-request). We'll then review and merge it.
In any case, thank you very much for your contributions!
+**Tip:** To test extractors that require login information, create a file `test/local_parameters.json` and add `"usenetrc": true` or your `username`&`password` or `cookiefile`/`cookiesfrombrowser` in it:
+```json
+{
+ "username": "your user name",
+ "password": "your password"
+}
+```
## yt-dlp coding conventions
This section introduces a guide lines for writing idiomatic, robust and future-proof extractor code.
-Extractors are very fragile by nature since they depend on the layout of the source data provided by 3rd party media hosters out of your control and this layout tends to change. As an extractor implementer your task is not only to write code that will extract media links and metadata correctly but also to minimize dependency on the source's layout and even to make the code foresee potential future changes and be ready for that. This is important because it will allow the extractor not to break on minor layout changes thus keeping old yt-dlp versions working. Even though this breakage issue may be easily fixed by a new version of yt-dlp, this could take some time, during which the the extractor will remain broken.
+Extractors are very fragile by nature since they depend on the layout of the source data provided by 3rd party media hosters out of your control and this layout tends to change. As an extractor implementer your task is not only to write code that will extract media links and metadata correctly but also to minimize dependency on the source's layout and even to make the code foresee potential future changes and be ready for that. This is important because it will allow the extractor not to break on minor layout changes thus keeping old yt-dlp versions working. Even though this breakage issue may be easily fixed by a new version of yt-dlp, this could take some time, during which the extractor will remain broken.
### Mandatory and optional metafields
-For extraction to work yt-dlp relies on metadata your extractor extracts and provides to yt-dlp expressed by an [information dictionary](yt_dlp/extractor/common.py#L91-L426) or simply *info dict*. Only the following meta fields in the *info dict* are considered mandatory for a successful extraction process by yt-dlp:
+For extraction to work yt-dlp relies on metadata your extractor extracts and provides to yt-dlp expressed by an [information dictionary](yt_dlp/extractor/common.py#L119-L440) or simply *info dict*. Only the following meta fields in the *info dict* are considered mandatory for a successful extraction process by yt-dlp:
- `id` (media identifier)
- `title` (media title)
- `url` (media download URL) or `formats`
-The aforementioned metafields are the critical data that the extraction does not make any sense without and if any of them fail to be extracted then the extractor is considered completely broken. While, in fact, only `id` is technically mandatory, due to compatability reasons, yt-dlp also treats `title` as mandatory. The extractor is allowed to return the info dict without url or formats in some special cases if it allows the user to extract usefull information with `--ignore-no-formats-error` - Eg: when the video is a live stream that has not started yet.
+The aforementioned metafields are the critical data that the extraction does not make any sense without and if any of them fail to be extracted then the extractor is considered completely broken. While all extractors must return a `title`, they must also allow it's extraction to be non-fatal.
+
+For pornographic sites, appropriate `age_limit` must also be returned.
+
+The extractor is allowed to return the info dict without url or formats in some special cases if it allows the user to extract useful information with `--ignore-no-formats-error` - e.g. when the video is a live stream that has not started yet.
[Any field](yt_dlp/extractor/common.py#219-L426) apart from the aforementioned ones are considered **optional**. That means that extraction should be **tolerant** to situations when sources for these fields can potentially be unavailable (even if they are always available at the moment) and **future-proof** in order not to break the extraction of general purpose mandatory fields.
The latter will break extraction process with `KeyError` if `summary` disappears from `meta` at some later time but with the former approach extraction will just go ahead with `description` set to `None` which is perfectly fine (remember `None` is equivalent to the absence of data).
-If the data is nested, do not use `.get` chains, but instead make use of the utility functions `try_get` or `traverse_obj`
+If the data is nested, do not use `.get` chains, but instead make use of `traverse_obj`.
Considering the above `meta` again, assume you want to extract `["user"]["name"]` and put it in the resulting info dict as `uploader`
-```python
-uploader = try_get(meta, lambda x: x['user']['name']) # correct
-```
-or
```python
uploader = traverse_obj(meta, ('user', 'name')) # correct
```
```python
uploader = meta.get('user', {}).get('name') # incorrect
```
+or
+```python
+uploader = try_get(meta, lambda x: x['user']['name']) # old utility
+```
Similarly, you should pass `fatal=False` when extracting optional data from a webpage with `_search_regex`, `_html_search_regex` or similar methods, for instance:
Another thing to remember is not to try to iterate over `None`
-Say you extracted a list of thumbnails into `thumbnail_data` using `try_get` and now want to iterate over them
+Say you extracted a list of thumbnails into `thumbnail_data` and want to iterate over them
```python
-thumbnail_data = try_get(...)
+thumbnail_data = data.get('thumbnails') or []
thumbnails = [{
- 'url': item['url']
-} for item in thumbnail_data or []] # correct
+ 'url': item['url'],
+ 'height': item.get('h'),
+} for item in thumbnail_data if item.get('url')] # correct
```
and not like:
```python
-thumbnail_data = try_get(...)
+thumbnail_data = data.get('thumbnails')
thumbnails = [{
- 'url': item['url']
+ 'url': item['url'],
+ 'height': item.get('h'),
} for item in thumbnail_data] # incorrect
```
-In the later case, `thumbnail_data` will be `None` if the field was not found and this will cause the loop `for item in thumbnail_data` to raise a fatal error. Using `for item in thumbnail_data or []` avoids this error and results in setting an empty list in `thumbnails` instead.
+In this case, `thumbnail_data` will be `None` if the field was not found and this will cause the loop `for item in thumbnail_data` to raise a fatal error. Using `or []` avoids this error and results in setting an empty list in `thumbnails` instead.
+Alternately, this can be further simplified by using `traverse_obj`
+
+```python
+thumbnails = [{
+ 'url': item['url'],
+ 'height': item.get('h'),
+} for item in traverse_obj(data, ('thumbnails', lambda _, v: v['url']))]
+```
+
+or, even better,
+
+```python
+thumbnails = traverse_obj(data, ('thumbnails', ..., {'url': 'url', 'height': 'h'}))
+```
### Provide fallbacks
#### Example
-Say `meta` from the previous example has a `title` and you are about to extract it. Since `title` is a mandatory meta field you should end up with something like:
+Say `meta` from the previous example has a `title` and you are about to extract it like:
```python
-title = meta['title']
+title = meta.get('title')
```
-If `title` disappears from `meta` in future due to some changes on the hoster's side the extraction would fail since `title` is mandatory. That's expected.
+If `title` disappears from `meta` in future due to some changes on the hoster's side the title extraction would fail.
-Assume that you have some another source you can extract `title` from, for example `og:title` HTML meta of a `webpage`. In this case you can provide a fallback scenario:
+Assume that you have some another source you can extract `title` from, for example `og:title` HTML meta of a `webpage`. In this case you can provide a fallback like:
```python
title = meta.get('title') or self._og_search_title(webpage)
```
-This code will try to extract from `meta` first and if it fails it will try extracting `og:title` from a `webpage`.
+This code will try to extract from `meta` first and if it fails it will try extracting `og:title` from a `webpage`, making the extractor more robust.
### Regular expressions
r'<span[^>]+class="title"[^>]*>([^<]+)', webpage, 'title')
```
-Or even better:
+which tolerates potential changes in the `style` attribute's value. Or even better:
```python
title = self._search_regex( # correct
webpage, 'title', group='title')
```
-Note how you tolerate potential changes in the `style` attribute's value or switch from using double quotes to single for `class` attribute:
+which also handles both single quotes in addition to double quotes.
The code definitely should not look like:
webpage, 'title', group='title')
```
-Here the presence or absence of other attributes including `style` is irrelevent for the data we need, and so the regex must not depend on it
+Here the presence or absence of other attributes including `style` is irrelevant for the data we need, and so the regex must not depend on it
+
+
+#### Keep the regular expressions as simple as possible, but no simpler
+
+Since many extractors deal with unstructured data provided by websites, we will often need to use very complex regular expressions. You should try to use the *simplest* regex that can accomplish what you want. In other words, each part of the regex must have a reason for existing. If you can take out a symbol and the functionality does not change, the symbol should not be there.
+
+##### Example
+
+Correct:
+
+```python
+_VALID_URL = r'https?://(?:www\.)?website\.com/(?:[^/]+/){3,4}(?P<display_id>[^/]+)_(?P<id>\d+)'
+```
+
+Incorrect:
+
+```python
+_VALID_URL = r'https?:\/\/(?:www\.)?website\.com\/[^\/]+/[^\/]+/[^\/]+(?:\/[^\/]+)?\/(?P<display_id>[^\/]+)_(?P<id>\d+)'
+```
+
+#### Do not misuse `.` and use the correct quantifiers (`+*?`)
+
+Avoid creating regexes that over-match because of wrong use of quantifiers. Also try to avoid non-greedy matching (`?`) where possible since they could easily result in [catastrophic backtracking](https://www.regular-expressions.info/catastrophic.html)
+
+Correct:
+
+```python
+title = self._search_regex(r'<span\b[^>]+class="title"[^>]*>([^<]+)', webpage, 'title')
+```
+
+Incorrect:
+
+```python
+title = self._search_regex(r'<span\b.*class="title".*>(.+?)<', webpage, 'title')
+```
### Long lines policy
-There is a soft limit to keep lines of code under 100 characters long. This means it should be respected if possible and if it does not make readability and code maintenance worse. Sometimes, it may be reasonable to go upto 120 characters and sometimes even 80 can be unreadable. Keep in mind that this is not a hard limit and is just one of many tools to make the code more readable
+There is a soft limit to keep lines of code under 100 characters long. This means it should be respected if possible and if it does not make readability and code maintenance worse. Sometimes, it may be reasonable to go upto 120 characters and sometimes even 80 can be unreadable. Keep in mind that this is not a hard limit and is just one of many tools to make the code more readable.
For example, you should **never** split long string literals like URLs or some other often copied entities over multiple lines to fit this limit:
+Conversely, don't unnecessarily split small lines further. As a rule of thumb, if removing the line split keeps the code under 80 characters, it should be a single line.
+
+##### Examples
+
Correct:
```python
'PLMYEtVRpaqY00V9W81Cwmzp6N6vZqfUKD4'
```
+Correct:
+
+```python
+uploader = traverse_obj(info, ('uploader', 'name'), ('author', 'fullname'))
+```
+
+Incorrect:
+
+```python
+uploader = traverse_obj(
+ info,
+ ('uploader', 'name'),
+ ('author', 'fullname'))
+```
+
+Correct:
+
+```python
+formats = self._extract_m3u8_formats(
+ m3u8_url, video_id, 'mp4', 'm3u8_native', m3u8_id='hls',
+ note='Downloading HD m3u8 information', errnote='Unable to download HD m3u8 information')
+```
+
+Incorrect:
+
+```python
+formats = self._extract_m3u8_formats(m3u8_url,
+ video_id,
+ 'mp4',
+ 'm3u8_native',
+ m3u8_id='hls',
+ note='Downloading HD m3u8 information',
+ errnote='Unable to download HD m3u8 information')
+```
+
+
+### Quotes
+
+Always use single quotes for strings (even if the string has `'`) and double quotes for docstrings. Use `'''` only for multi-line strings. An exception can be made if a string has multiple single quotes in it and escaping makes it *significantly* harder to read. For f-strings, use you can use double quotes on the inside. But avoid f-strings that have too many quotes inside.
+
+
### Inline values
Extracting variables is acceptable for reducing code duplication and improving readability of complex expressions. However, you should avoid extracting variables used only once and moving them to opposite parts of the extractor file, which makes reading the linear flow difficult.
-#### Example
+#### Examples
Correct:
```python
-title = self._html_search_regex(r'<title>([^<]+)</title>', webpage, 'title')
+return {
+ 'title': self._html_search_regex(r'<h1>([^<]+)</h1>', webpage, 'title'),
+ # ...some lines of code...
+}
```
Incorrect:
```python
-TITLE_RE = r'<title>([^<]+)</title>'
+TITLE_RE = r'<h1>([^<]+)</h1>'
# ...some lines of code...
title = self._html_search_regex(TITLE_RE, webpage, 'title')
+# ...some lines of code...
+return {
+ 'title': title,
+ # ...some lines of code...
+}
```
### Trailing parentheses
-Always move trailing parentheses after the last argument.
+Always move trailing parentheses used for grouping/functions after the last argument. On the other hand, multi-line literal list/tuple/dict/set should closed be in a new line. Generators and list/dict comprehensions may use either style
-Note that this *does not* apply to braces `}` or square brackets `]` both of which should closed be in a new line
+#### Examples
-#### Example
+Correct:
+```python
+url = traverse_obj(info, (
+ 'context', 'dispatcher', 'stores', 'VideoTitlePageStore', 'data', 'video', 0, 'VideoUrlSet', 'VideoUrl'), list)
+```
Correct:
```python
- lambda x: x['ResultSet']['Result'][0]['VideoUrlSet']['VideoUrl'],
+url = traverse_obj(
+ info,
+ ('context', 'dispatcher', 'stores', 'VideoTitlePageStore', 'data', 'video', 0, 'VideoUrlSet', 'VideoUrl'),
list)
```
Incorrect:
```python
- lambda x: x['ResultSet']['Result'][0]['VideoUrlSet']['VideoUrl'],
- list,
+url = traverse_obj(
+ info,
+ ('context', 'dispatcher', 'stores', 'VideoTitlePageStore', 'data', 'video', 0, 'VideoUrlSet', 'VideoUrl'),
+ list
)
```
+Correct:
+
+```python
+f = {
+ 'url': url,
+ 'format_id': format_id,
+}
+```
+
+Incorrect:
+
+```python
+f = {'url': url,
+ 'format_id': format_id}
+```
+
+Correct:
+
+```python
+formats = [process_formats(f) for f in format_data
+ if f.get('type') in ('hls', 'dash', 'direct') and f.get('downloadable')]
+```
+
+Correct:
+
+```python
+formats = [
+ process_formats(f) for f in format_data
+ if f.get('type') in ('hls', 'dash', 'direct') and f.get('downloadable')
+]
+```
+
### Use convenience conversion and parsing functions
-Wrap all extracted numeric data into safe functions from [`yt_dlp/utils.py`](yt_dlp/utils.py): `int_or_none`, `float_or_none`. Use them for string to number conversions as well.
+Wrap all extracted numeric data into safe functions from [`yt_dlp/utils/`](yt_dlp/utils/): `int_or_none`, `float_or_none`. Use them for string to number conversions as well.
Use `url_or_none` for safe URL processing.
-Use `try_get`, `dict_get` and `traverse_obj` for safe metadata extraction from parsed JSON.
+Use `traverse_obj` and `try_call` (superseeds `dict_get` and `try_get`) for safe metadata extraction from parsed JSON.
Use `unified_strdate` for uniform `upload_date` or any `YYYYMMDD` meta field extraction, `unified_timestamp` for uniform `timestamp` extraction, `parse_filesize` for `filesize` extraction, `parse_count` for count meta fields extraction, `parse_resolution`, `parse_duration` for `duration` extraction, `parse_age_limit` for `age_limit` extraction.
-Explore [`yt_dlp/utils.py`](yt_dlp/utils.py) for more useful convenience functions.
+Explore [`yt_dlp/utils/`](yt_dlp/utils/) for more useful convenience functions.
-#### More examples
+#### Examples
-##### Safely extract optional description from parsed JSON
```python
description = traverse_obj(response, ('result', 'video', 'summary'), expected_type=str)
-```
-
-##### Safely extract more optional metadata
-```python
+thumbnails = traverse_obj(response, ('result', 'thumbnails', ..., 'url'), expected_type=url_or_none)
video = traverse_obj(response, ('result', 'video', 0), default={}, expected_type=dict)
-description = video.get('summary')
duration = float_or_none(video.get('durationMs'), scale=1000)
view_count = int_or_none(video.get('views'))
```
+# My pull request is labeled pending-fixes
+
+The `pending-fixes` label is added when there are changes requested to a PR. When the necessary changes are made, the label should be removed. However, despite our best efforts, it may sometimes happen that the maintainer did not see the changes or forgot to remove the label. If your PR is still marked as `pending-fixes` a few days after all requested changes have been made, feel free to ping the maintainer who labeled your issue and ask them to re-review and remove the label.
+
+
# EMBEDDING YT-DLP
projects / yt-dlp.git / blobdiff