For the web scraping component against https://talkpython.fm I was successful using the sync libraries and code with a 3.6 interpreter, however when moving on to the async version I get:

aiohttp.client_exceptions.ClientConnectorSSLError: Cannot connect to host talkpython.fm:443 ssl:None [[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)]

There is a use of an alias in chapter 04-asyncio to set up a virtual environment but it is not very clear what command is exactly used.
Could we have this included somewhere in the code or course materials. I am assuming it is something along the lines of:
alias venv='python3 -m venv venv && . venv/bin/activate && pip install --upgrade pip > /dev/null && pip install --upgrade setuptools > /dev/null'

This seemed to produce a similar product shown in the video.

Hi

Don't understand how it works for you in the demo but when i run it crases straight away. I have tried multiple times and when i try to start 04-asyncio/web_scraping/async_scrape/program.py i get the following error.

python program.py
Traceback (most recent call last):
File "program.py", line 58, in
main()
File "program.py", line 32, in main
loop.run_until_complete(get_title_range())
File "/usr/lib/python3.6/asyncio/base_events.py", line 468, in run_until_complete
return future.result()
File "program.py", line 49, in get_title_range
tasks.append((n, asyncio.create_task(get_html(n))))
AttributeError: module 'asyncio' has no attribute 'create_task'

Using pipenv:
aiodns==1.1.1
aiohttp==3.4.4
async-timeout==3.0.0
attrs==18.2.0
beautifulsoup4==4.6.3
bs4==0.0.1
cchardet==2.1.4
chardet==3.0.4
colorama==0.3.9
idna-ssl==1.1.0; python_version < '3.7'
idna==2.7
multidict==4.4.2
pycares==2.3.0
yarl==1.2.6

python --version
Python 3.6.6

Bumped in to the use of f-strings relatively early on. I am using Ubuntu 16.04 which has python 3.5 by default, which does not support f-strings.
I raised a couple of pull requests for chapter 04-asyncio but haven't yet gone further.

Using grep, I located additional files that may have issues:
grep -rnw . -e "f[\'\"]"

./src/09-built-on-asyncio/the_trio/prod_sync.py:24: print(colorama.Fore.YELLOW + f" -- generated item {idx}", flush=True)
./src/09-built-on-asyncio/the_trio/prod_asyncio.py:32: print(colorama.Fore.YELLOW + f" -- generated item {idx}", flush=True)
./src/09-built-on-asyncio/the_trio/prod_trio.py:29: print(colorama.Fore.YELLOW + f" -- generated item {idx}", flush=True)
./src/10-async-web/acityscape_api/config/settings.py:6: file = os.path.join(os.path.dirname(file), f"{mode}.json")
./src/10-async-web/acityscape_api/services/location_service.py:16: key = f'{zip_code}, {country}'
./src/10-async-web/acityscape_api/services/location_service.py:29: city_data = data.get(f'{zip_code}, {country}', dict())
./src/10-async-web/cityscape_api/config/settings.py:6: file = os.path.join(os.path.dirname(file), f"{mode}.json")
./src/10-async-web/cityscape_api/services/location_service.py:14: key = f'{zip_code}, {country}'
./src/10-async-web/cityscape_api/services/location_service.py:26: city_data = data.get(f'{zip_code}, {country}', dict())
./src/04-asyncio/producer_consumer/prod_async/async_program.py:32: #print(colorama.Fore.YELLOW + f" -- generated item {idx}", flush=True)
./src/04-asyncio/producer_consumer/prod_sync/sync_program.py:23: #print(colorama.Fore.YELLOW + f" -- generated item {idx}", flush=True)
./src/05-threads/basic_threads/threaded_prod.py:44: print(colorama.Fore.YELLOW + f" -- generated item {idx}", flush=True)
./src/05-threads/basic_threads/sync_prod.py:25: print(colorama.Fore.YELLOW + f" -- generated item {idx}", flush=True)

Python 3.10 has changed how this works and deprecated how we've been starting asyncio.

This might be a wired way of reaching out but, I have checked why the threaded example for 05-threads/cpu_attempt/compute_threaded.py is ~15% faster than non threaded one.
Basically the threaded version does computation on floats because of the devisions you make, whereas synchronous example uses ints. So apparently the floats computations are a bit faster than integer ones.

In the video for async and await with asyncio [ch4/12]: Demo: Understanding basic generators [v3/14] , the video hangs at 7:07.

I've tried exiting and reloading the video, to no avail.
If this isn't an issue with the file, what can I do my end?

Hi Michael,

Getting aiohttp errors when executing the async version of the web scraper for your site. Running OSX Catalina and (official) Python 3.8.1.

 File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/aiohttp/connector.py", line 938, in _wrap_create_connection
    raise ClientConnectorCertificateError(
aiohttp.client_exceptions.ClientConnectorCertificateError: Cannot connect to host talkpython.fm:443 ssl:True [SSLCertVerificationError: (1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1108)')]

I'm running into the below error
ClientConnectorError Cannot connect to host www.datasciencetoolkit.org:80 ssl:default [nodename nor servname provided, or not known]
any ideas ?

aiohttp stopped installing cchardet speedup under >Python 3.9 (See aio-libs/aiohttp#6857) due to cchardet being unmaintained. I ran async_scrape/program.py successfully without cchardet using python 3.9 and 3.10. I'll send a PR if it makes sense to remove cchardet from the requirements.txt.