7 files changed, 32 insertions, 38 deletions
diff --git a/bot/exts/info/doc/_cog.py b/bot/exts/info/doc/_cog.py
index e7710db24..ca6af946b 100644
--- a/bot/exts/info/doc/_cog.py
+++ b/bot/exts/info/doc/_cog.py
@@ -13,6 +13,7 @@ import aiohttp
 import discord
 from discord.ext import commands
 
+from bot.api import ResponseCodeError
 from bot.bot import Bot
 from bot.constants import MODERATION_ROLES, RedirectOutput
 from bot.converters import Inventory, PackageName, ValidURL, allowed_strings
@@ -395,7 +396,14 @@ class DocCog(commands.Cog):
             "base_url": base_url,
             "inventory_url": inventory_url
         }
-        await self.bot.api_client.post("bot/documentation-links", json=body)
+        try:
+            await self.bot.api_client.post("bot/documentation-links", json=body)
+        except ResponseCodeError as err:
+            if err.status == 400 and "already exists" in err.response_json.get("package", [""])[0]:
+                log.info(f"Ignoring HTTP 400 as package {package_name} has already been added.")
+                await ctx.send(f"Package {package_name} has already been added.")
+                return
+            raise
 
         log.info(
             f"User @{ctx.author} ({ctx.author.id}) added a new documentation package:\n"
diff --git a/bot/resources/tags/async-await.md b/bot/resources/tags/async-await.md
index ff71ace07..01ab28fe3 100644
--- a/bot/resources/tags/async-await.md
+++ b/bot/resources/tags/async-await.md
@@ -2,27 +2,26 @@
 
 Python provides the ability to run multiple tasks and coroutines simultaneously with the use of the `asyncio` library, which is included in the Python standard library.
 
-This works by running these coroutines in an event loop, where the context of which coroutine is being run is switches periodically to allow all of them to run, giving the appearance of running at the same time. This is different to using threads or processes in that all code is run in the main process and thread, although it is possible to run coroutines in threads.
+This works by running these coroutines in an event loop, where the context of the running coroutine switches periodically to allow all other coroutines to run, thus giving the appearance of running at the same time. This is different to using threads or processes in that all code runs in the main process and thread, although it is possible to run coroutines in other threads.
 
 To call an async function we can either `await` it, or run it in an event loop which we get from `asyncio`.
 
-To create a coroutine that can be used with asyncio we need to define a function using the async keyword:
+To create a coroutine that can be used with asyncio we need to define a function using the `async` keyword:
 ```py
 async def main():
     await something_awaitable()
 ```
-Which means we can call `await something_awaitable()` directly from within the function. If this were a non-async function this would have raised an exception like: `SyntaxError: 'await' outside async function`
+Which means we can call `await something_awaitable()` directly from within the function. If this were a non-async function, it would raise the exception `SyntaxError: 'await' outside async function`
 
-To run the top level async function from outside of the event loop we can get an event loop from `asyncio`, and then use that loop to run the function:
+To run the top level async function from outside the event loop we need to use [`asyncio.run()`](https://docs.python.org/3/library/asyncio-task.html#asyncio.run), like this:
 ```py
-from asyncio import get_event_loop
+import asyncio
 
 async def main():
     await something_awaitable()
 
-loop = get_event_loop()
-loop.run_until_complete(main())
+asyncio.run(main())
 ```
-Note that in the `run_until_complete()` where we appear to be calling `main()`, this does not execute the code in `main`, rather it returns a `coroutine` object which is then handled and run by the event loop via `run_until_complete()`.
+Note that in the `asyncio.run()`, where we appear to be calling `main()`, this does not execute the code in `main`. Rather, it creates and returns a new `coroutine` object (i.e `main() is not main()`) which is then handled and run by the event loop via `asyncio.run()`.
 
 To learn more about asyncio and its use, see the [asyncio documentation](https://docs.python.org/3/library/asyncio.html).
diff --git a/bot/resources/tags/traceback.md b/bot/resources/tags/traceback.md
index e770fa86d..321737aac 100644
--- a/bot/resources/tags/traceback.md
+++ b/bot/resources/tags/traceback.md
@@ -1,4 +1,4 @@
-Please provide a full traceback to your exception in order for us to identify your issue.
+Please provide the full traceback for your exception in order to help us identify your issue.
 
 A full traceback could look like:
 ```py
@@ -6,13 +6,13 @@ Traceback (most recent call last):
     File "tiny", line 3, in
         do_something()
     File "tiny", line 2, in do_something
-        a = 6 / 0
-ZeroDivisionError: integer division or modulo by zero
+        a = 6 / b
+ZeroDivisionError: division by zero
 ```
 The best way to read your traceback is bottom to top.
 
-• Identify the exception raised (e.g. ZeroDivisionError)  
-• Make note of the line number, and navigate there in your program.  
-• Try to understand why the error occurred.  
+• Identify the exception raised (in this case `ZeroDivisionError`)  
+• Make note of the line number (in this case `2`), and navigate there in your program.  
+• Try to understand why the error occurred (in this case because `b` is `0`).
 
-To read more about exceptions and errors, please refer to the [PyDis Wiki](https://pythondiscord.com/pages/asking-good-questions/#examining-tracebacks) or the [official Python tutorial.](https://docs.python.org/3.7/tutorial/errors.html)
+To read more about exceptions and errors, please refer to the [PyDis Wiki](https://pythondiscord.com/pages/guides/pydis-guides/asking-good-questions/#examining-tracebacks) or the [official Python tutorial](https://docs.python.org/3.7/tutorial/errors.html).
diff --git a/bot/resources/tags/windows-path.md b/bot/resources/tags/windows-path.md
index da8edf685..b2b0da029 100644
--- a/bot/resources/tags/windows-path.md
+++ b/bot/resources/tags/windows-path.md
@@ -1,30 +1,17 @@
 **PATH on Windows**
 
-If you have installed Python but you forgot to check the *Add Python to PATH* option during the installation you may still be able to access your installation with ease.
+If you have installed Python but forgot to check the `Add Python to PATH` option during the installation, you may still be able to access your installation with ease.
 
-If you did not uncheck the option to install the Python launcher then you will find a `py` command on your system. If you want to be able to open your Python installation by running `python` then your best option is to re-install Python.
+If you did not uncheck the option to install the `py launcher`, then you'll instead have a `py` command which can be used in the same way. If you want to be able to access your Python installation via the `python` command, then your best option is to re-install Python (remembering to tick the `Add Python to PATH` checkbox).
 
-Otherwise, you can access your install using the `py` command in Command Prompt. Where you may type something with the `python` command like:
-```
-C:\Users\Username> python3 my_application_file.py
-```
-
-You can achieve the same result using the `py` command like this:
-```
-C:\Users\Username> py -3 my_application_file.py
-```
-
-You can pass any options to the Python interpreter after you specify a version, for example, to install a Python module using `pip` you can run:
-```
-C:\Users\Username> py -3 -m pip install numpy
-```
+You can pass any options to the Python interpreter, e.g. to install the `[numpy](https://pypi.org/project/numpy/)` module from PyPI you can run `py -3 -m pip install numpy` or `python -m pip install numpy`.
 
-You can also access different versions of Python using the version flag, like so:
+You can also access different versions of Python using the version flag of the `py` command, like so:
 ```
 C:\Users\Username> py -3.7
 ... Python 3.7 starts ...
 C:\Users\Username> py -3.6
-... Python 3.6 stars ...
+... Python 3.6 starts ...
 C:\Users\Username> py -2
 ... Python 2 (any version installed) starts ...
 ```
diff --git a/bot/resources/tags/xy-problem.md b/bot/resources/tags/xy-problem.md
index b77bd27e8..8c508f18c 100644
--- a/bot/resources/tags/xy-problem.md
+++ b/bot/resources/tags/xy-problem.md
@@ -1,7 +1,7 @@
 **xy-problem**
 
-Asking about your attempted solution rather than your actual problem.
+The XY problem can be summarised as asking about your attempted solution, rather than your actual problem.
 
 Often programmers will get distracted with a potential solution they've come up with, and will try asking for help getting it to work. However, it's possible this solution either wouldn't work as they expect, or there's a much better solution instead.
 
-For more information and examples: http://xyproblem.info/
+For more information and examples, see http://xyproblem.info/
diff --git a/bot/resources/tags/ytdl.md b/bot/resources/tags/ytdl.md
index f96b7f853..68a0a0cdb 100644
--- a/bot/resources/tags/ytdl.md
+++ b/bot/resources/tags/ytdl.md
@@ -1,4 +1,4 @@
-Per [Python Discord's Rule 5](https://pythondiscord.com/pages/rules), we are unable to assist with questions related to youtube-dl, pytube, or other YouTube video downloaders as their usage violates YouTube's Terms of Service.
+Per [Python Discord's Rule 5](https://pythondiscord.com/pages/rules), we are unable to assist with questions related to youtube-dl, pytube, or other YouTube video downloaders, as their usage violates YouTube's Terms of Service.
 
 For reference, this usage is covered by the following clauses in [YouTube's TOS](https://www.youtube.com/static?gl=GB&template=terms), as of 2021-03-17:
 ```
diff --git a/bot/resources/tags/zip.md b/bot/resources/tags/zip.md
index 6b05f0282..6f3157f71 100644
--- a/bot/resources/tags/zip.md
+++ b/bot/resources/tags/zip.md
@@ -3,7 +3,7 @@ The zip function allows you to iterate through multiple iterables simultaneously
 ```py
 letters = 'abc'
 numbers = [1, 2, 3]
-# zip(letters, numbers) --> [('a', 1), ('b', 2), ('c', 3)]
+# list(zip(letters, numbers)) --> [('a', 1), ('b', 2), ('c', 3)]
 for letter, number in zip(letters, numbers):
     print(letter, number)
 ```