2022

Introduction ⚑

New: Xprop.

You can use xprop to get the name and details of any running graphic application by clicking on it.

Computer Science⚑

CICD⚑

Github Actions ⚑

New: Store file as a secret.

If you want to store a file (multiline, binary...) as a secret, first encode it with base64:
```
base64 -i < {{ file_path }} | tr -d '\n' | xclip -i -selection clipboard
```
Then paste it to a new secret. To restore the file diring the workflow, add:
```
- name: restore file
  run: echo ${{ secrets.SECRET }} | base64 -d > {{ file_path }}
```

New: Conditional execution.

To allow a step to fail without that implying failing the whole workflow and then execute some steps according to the result, do:

- name: commitizen
  id: commitizen
  continue-on-error: true
  uses: commitizen-tools/commitizen-action@0.11.0
  with:
    github_token: ${{ secrets.GITHUB_TOKEN }}

- name: Some other task
  if: steps.commitizen.outcome == 'success'
  run: something

DBMS⚑

Hardware ⚑

New: Sticky touchpad after suspend.

After suspension, the touchpad behaves weird: can't scroll, and acts as if you were clicking and dragging (sticky). The TrackPoint works correctly though.

A first solution was to disable it and just use the TrackPoint. This is done as follows:
```
xinput list # look for SynPS/2 Synaptics TouchPad
xinput set-prop <number> "Device Enabled" 0
```
This allows you to use the computer without the sticky mouse annoyance but doesn't actually solve the problem. For that, the solution that worked for me is removing the psmouse kernel module before suspending and then reloading it after waking up from suspension. You can first try to do this manualy and then if it works create this script in /lib/systemd/system-sleep/psmouse:
```
case $1/$2 in
  pre/*)
    echo "Going to $2..."
    modprobe -r psmouse
    ;;
  post/*)
    echo "Waking up from $2..."
    sleep 2
    modprobe psmouse
    ;;
esac
```

Programming⚑

``python session.put('http://httpbin.org/put', data=b'data') session.delete('http://httpbin.org/delete') session.head('http://httpbin.org/get') session.options('http://httpbin.org/get') session.patch('http://httpbin.org/patch', data=b'data')

New: Headers.

headers = {
    'Accepts': 'application/json',
    'X-API_KEY': 'secret',
}

async with aiohttp.ClientSession(headers=headers) as session:
    ...

New: Types in the Closure Type System.
- Types in the Closure Type System

JSDoc ⚑

New: JSDoc @example.

`javascript /** * Solves equations of the form a * x = b * @example * // returns 2 * globalNS.method1(5, 10); * @example * // returns 3 * globalNS.method(5, 15); * @returns {Number} Returns the value of x for the equation. */ globalNS.method1 = function (a, b) { return b / a; };
New: JSDoc @type.

Reference: Use JSDoc: @type.

Jinja ⚑

New: InkWell.

Make a component clickable (with animations onf hover and tap):

InkWell(
    onTap: () {
      // To do
    },
    child: Card(),
)

New: Accessing the parent Loop.

The special loop variable always points to the innermost loop. If it’s desired to have access to an outer loop it’s possible to alias it:

<table>
{% for row in table %}
  <tr>
  {% set rowloop = loop %}
  {% for cell in row %}
    <td id="cell-{{ rowloop.index }}-{{ loop.index }}">{{ cell }}</td>
  {% endfor %}
  </tr>
{% endfor %}
</table>

Basics ⚑

New: Adjust default plot size.

Try running %matplotlib notebook after the imports.

New: Enumerate().

To iterate over a list keys and values use enumerate(). Example:

some_list = ['a', 'b', 'c']
for index, value in enumerate(some_list):
  ...

New: Enum.

Example:

from enum import Enum

class Color(Enum):
  RED = 1
  GREEN = 2
  BLUE = 3

New: Enum examples.

>>> Color(1)
<Color.RED: 1>
>>> Color(3)
<Color.BLUE: 3>

>>> Color['RED']
<Color.RED: 1>
>>> Color['GREEN']
<Color.GREEN: 2>

>>> member = Color.RED
>>> member.name
'RED'
>>> member.value
1

New: Datetime nstance methods.
- isoformat(): ISO 8601 formatted string.
New: Check syntax without running.

Try to compile it:
```
python -m py_compile script.py
```

Debugging ⚑

New: Flutter Provider.

A relatively simple and efficient tool for state management in Flutter is provider.
New: Better-exceptions.

Pretty and more helpful exceptions in Python, automatically.
```
pip install better_exceptions
export BETTER_EXCEPTIONS=1
```

New: Debugging with inspect.

See a function definition at runtime

from somewhere import somefunction
from inspect import getsource

print(getsource(somefunction))

Get function signature at runtime

from somewhere import somefunction
from inspect import signature

print(signature(somefunction))

Logging ⚑

New: Python logging.

Basic configuration:

import logging

logging.basicConfig(
    format='%(asctime)s %(levelname)s %(message)s',
    level=logging.INFO,
    datefmt='%Y-%m-%d %H:%M:%S'
)

logging.info('Just a random string...')

pip ⚑

New: Uninstall all packages.
```
pip freeze | xargs pip uninstall -y
```
New: Install.

Options:
- --ignore-installed: Ignore the installed packages, overwriting them.

pydantic ⚑

New: Logging.

To add custom log messages to the uvicorn output, the dirty way, get the logger called uvicorn:
```
logger = logging.getLogger("uvicorn")
```
New: Pydantic types.
- pydantic.HttpUrl
- pydantic.color.Color
New: Exporting.

Options:
- model.json(exclude_none=True)
- model.dict(exclude_none=True)
New: Use alias for model.dict().

From https://github.com/pydantic/pydantic/issues/205

Typing ⚑

New: Awaitable type.
- Awaitable: Promise/Future.
New: F821 undefined name when class method return type is the class name.

Since the class is not defined yet, to use it as the return type that a class method returns you need to:
```
from __future__ import annotations
```

Theory⚑

Algorithms ⚑

New: Add union-find data structure definition and algorithms.

In computer science, a disjoint-set data structure, also called a union–find data structure or merge–find set, is a data structure that stores a collection of disjoint (non-overlapping) sets.

It can be used to store the connected components of an undirected graph.

An example could be:
```
0   1---2   3---4

5---6   7   8   9
```
- N is the number of nodes. Equals to 10 in the example.
The data structure should support the following operations:
- initialize(): Set the initial state of the graph.
- find(p, q): Are nodes p and q connected?
- union(p,q): Connect nodes p and q.

Media⚑

Books⚑

Atlas Shrugged ⚑

New: Atlas Shrugged 1957 novel by Ayn Rand.

Atlas Shrugged is a 1957 novel by Ayn Rand. It contains Rand's most extensive statement of Objectivism. The book depicts a dystopian United States in which private businesses suffer under increasingly burdensome laws and regulations.

The book is more than a thousand pages long. There are audiobooks (~60h long) and a movie divided in three parts.

The Problem of Political Authority ⚑

New: The Problem of Political Authority.

Modern states commonly deploy coercion in a wide array of circumstances in which the resort to force would clearly be wrong for any private agent. What entitles the state to behave in this manner? And why should citizens obey its commands? This book examines theories of political authority, from the social contract theory, to theories of democratic authorization, to fairness- and consequence-based theories. Ultimately, no theory of authority succeeds, and thus no government has the kind of authority often ascribed to governments.

The author goes on to discuss how voluntary and competitive institutions could provide the central goods for the sake of which the state is often deemed necessary, including law, protection from private criminals, and national security. An orderly and livable society thus does not require acquiescence in the illusion of political authority.

Other⚑

New: Flutter commnad version.

flutter --version: See Flutter and Dart version.

New: Enum.

enum Day { monday, tuesday }

Get the value of an enum element:

Day.monday.name

New: If null operator (??).

Get a default value if object is null:
```
var value;
...
value = value ?? 2;
```

New: Request a new certificate.

If there is no HTTP sever running:

certbot certonly --standalone --preferred-challenges http-01 -d {{ domain }} --register-unsafely-without-email --agree-tos -n

If there is an HTTP running:

certonly --webroot -w {{ web_path_letsencrypt }} --preferred-challenges http-01 -d {{ domain }} --register-unsafely-without-email --agree-tos -n

Correction: Add missing entries to nav.
New: Upload to Play Store with CI.
1. Create a principal in https://console.cloud.google.com/iam-admin/iam with the role Service Account User.
2. Create and download a new key (JSON format) for the created principal.
3. In Play Console go to Setup>API access and enable access for the created principal granting Admin (all permissions) to it.
4. Add the key JSON content as a GitHub Secret (e.g., SERVICE_ACCOUNT_JSON).
5. Add the following step to your workflow (after flutter build appbundle):
```
- name: Upload to Google Play
  uses: r0adkll/upload-google-play@v1.0.15
  with:
    serviceAccountJsonPlainText: ${{ secrets.SERVICE_ACCOUNT_JSON }}
    packageName: {{ package_name }}
    releaseFiles: build/app/outputs/bundle/release/app-release.aab
    track: production
```
New: Support named routes.

To support named routes (e.g., APP_HOST/some/route), add the following configuration to the host configuration file:
```
location / {
    try_files $uri $uri/ /index.html;
}
```
Otherwise NGINX will return 404 when queried for a named route since the corresponding file won't exist in the root directory.
New: Array find method.

.find(): returns the first element in the provided array that satisfies the provided testing function. If no values satisfy the testing function, undefined is returned. E.g., array1.find(element => element > 10).

New: Iterate keys and values.

for (const [key, value] of Object.entries(object)) {
  console.log(key, value);
}

Reorganization: Renamed duplicated filenames.