Today's problem description: https://adventofcode.com/2019/day/16

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

This is a recurring post to discuss programming or other technical projects that we've been working on. Tell us about one of your recent projects, either at work or personal projects. What's interesting about it? Are you having trouble with anything?

Today's problem description: https://adventofcode.com/2019/day/13

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

This is a recurring post to discuss programming or other technical projects that we've been working on. Tell us about one of your recent projects, either at work or personal projects. What's interesting about it? Are you having trouble with anything?

Today's problem description: https://adventofcode.com/2019/day/12

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

Today's problem description: https://adventofcode.com/2019/day/11

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

I've been trying to learn CSS. I went through the relevant sections of Colt Steele's Web Bootcamp. It is mostly focused on Bootstrap, which disappointed me a bit. So I went through MDN to learn Flexbox and CSS Grid, which seemed like a better alternative. The fundamentals are easy enough, but when I try to make a layout everything gets mixed in my head (even though I have the documentation open at all times). The impression I get is that modern CSS is not one thing, but a bunch of little things that resemble each other in a confusing way. It's hard to infer stuff and there are gotchas everywhere. I know this is not a programming language, but it is at least programming-related. Learning CSS feels more like learning English than a technology: you must accept that it's not a cohesive system, but rather the culmination of a long historical process full of random developments.

I tried getting back to Bootstrap, but then I have to override a bunch of stuff I don't even know is there.

I'm having a lot of trouble trying to put something very simple together. I just wanna leave that behind and go back to my beloved Python.

I did not want this to be a rant, but it is now a rant. So be it :P

This post has now a soundtrack.

Today's problem description: https://adventofcode.com/2019/day/9

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

Today's problem description: https://adventofcode.com/2019/day/5

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

I'm looking to get a couple of remote controlled dimmer sockets for a quite specific use case (heat lamps in a tortoise enclosure), and I'd like to control them directly from a Raspberry Pi. I've found a couple of decent looking fairly generic options - examples from Trust and TKB - and there seem to be several appropriate radio modules, either USB or GPIO.

Detecting and pairing with devices seems (hopefully) straightforward. My sticking point is trying to figure out how standardised the actual messaging is; there seem to be several brands of hub and device that can be used interchangeably, but a few that can't. In my case, of course, the RasPi will be taking the position of the hub and speaking to the devices directly.

I'm having trouble finding reliable info on whether a command like "dim to 70%", or "read output power" will be the same across all devices, whether it will follow some kind of standard but it may be one of several competing formats, or whether it's completely proprietary.

Any insight on how easy it is to programatically talk to these things would be very much appreciated!

Today's problem description: https://adventofcode.com/2019/day/8

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

Today's problem description: https://adventofcode.com/2019/day/3

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

Today's problem description: https://adventofcode.com/2019/day/2

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

Today's problem description: https://adventofcode.com/2019/day/4

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

Today's problem description: https://adventofcode.com/2019/day/1

Join the Tildes private leaderboard! You can do that on this page, by entering join code 730956-de85ce0c.

Please post your solutions in your own top-level comment. Here's a template you can copy-paste into your comment to format it nicely, with the code collapsed by default inside an expandable section with syntax highlighting (you can replace python with any of the "short names" listed in this page of supported languages):

<details>
<summary>Part 1</summary>

```python
Your code here.
```

</details>

This is a recurring post to discuss programming or other technical projects that we've been working on. Tell us about one of your recent projects, either at work or personal projects. What's interesting about it? Are you having trouble with anything?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?