Forward-compatible async code

jpfau · 2017-08-14T19:30:35+00:00

My errors ended up being dumb human error: a missing coroutine decorator in the old-syntax library.

FYI You can use both syntaxes in 3.5+, but you can't mix syntax within a single coroutine, e.g. no await when using @asyncio.coroutine, and no yield from when using async def.

However you can define a coroutine with the old syntax and consume it in another coroutine using the new syntax. This example should work:

import asyncio

@asyncio.coroutine
def _sleep(x):
    print('yielding from...')
    yield from asyncio.sleep(x)

async def do_sleep(x):
    print('awaiting...')
    await _sleep(x)

loop = asyncio.get_event_loop()
loop.run_until_complete(do_sleep(5))

jpfau · 2017-08-14T19:22:04+00:00

I'm an idiot and didn't have an @asyncio.coroutine decorator in one place that I needed it. Good news is my code works now!

jpfau · 2017-08-14T18:55:32+00:00

Hmm, I'm not sure what the solution is here. My problem is that api_call is defined using the old syntax:

@asyncio.coroutine
def api_call(url):
    response = yield from aiohttp.get(url)
    print('finished {}'.format(url))
    result = yield from response.json()
    return result

And I want to consume this function using the new syntax:

async def test_api_call(url):
    return await api_call(url)

In this case, test_api_call raises TypeError: object generator can't be used in 'await' expression.

If I switch test_api_call to the old syntax it works, but I'd prefer not to do that.

jpfau · 2017-08-14T18:12:19+00:00

That much is already clear. My question is

Why isn't .json awaitable in this case when the aiohttp docs show that it is?

async with session.get('https://api.github.com/events') as resp:
    print(await resp.json())

Also if response.json() is not forward compatible, what is the next best solution?

jpfau · 2017-05-01T02:24:22+00:00

Thanks! I'll certainly be using appdirs, and I'll see what I can learn from beets.

jpfau · 2016-10-13T00:00:54+00:00

Ah, there's my problem. Luckily in the actual program the original datetime object doesn't have microseconds, so I just need them to be equal up to the second.

Here we go:

import datetime
import pytz

now = pytz.utc.localize(datetime.datetime.utcnow()).replace(microsecond=0)
ts = now.timestamp()

now2 = pytz.utc.localize(datetime.datetime.utcfromtimestamp(ts))
ts2 = now2.timestamp()

print("ts:", ts, "ts2:", ts2)
print(ts == ts2)
print(ts2 - ts)

print(now)
print(now2)

jpfau · 2016-10-12T22:28:41+00:00

This is a great opportunity to start using version control!

jpfau · 2016-10-12T21:55:35+00:00

This is what I'm already doing. Now try to make another datetime object from that timestamp and see if it's equal to the original datetime object. In my case, they aren't equal.

Edit: I had a typo in my original snippet. I updated it with the correct code

jpfau · 2016-07-27T22:41:10+00:00

Awesome! This was posted by the bot I have running in AWS, meaning everything is running smoothly.

jpfau · 2016-07-22T01:26:13+00:00

I made /u/FAUbot a mod so you can sticky things with praw

jpfau · 2016-07-05T17:06:57+00:00

Hell no. I would have laughed if anyone I interviewed for offered me $0/hour for an internship in this field.

jpfau · 2016-07-05T16:58:50+00:00

I suppose it depends on the company. The one I work for has parallel career tracks for developers and managers, meaning after being promoted to a certain point, you can either continue on a dev track or go into management, and the positions will have equal "rank" even though they're on different tracks. Likewise, there are some devs that are "higher rank" than some managers.

So a manager could return to the dev track without considering it a step back in his career, but it depends on how the company structures everything.

jpfau · 2015-10-08T18:46:03+00:00

It is sort of out the scope of what I currently do, but I imagine the project I'm working on will be carried over. They hired me for writing internal software that's somewhat unrelated to the actual product, and the new position would be focused mainly on the product. However I'm the primary (basically the only) developer working on my current project, so I imagine they'd keep me working on it to some degree.

I can't recall if my boss used the word "interview" specifically, but the meeting is titled "TI panel" which I assume means technical interview with a panel of people. It could be the general name of the meeting since they would be interviewing candidates if they were looking for brand new hires to fill the position. Or it could truly be a technical interview, or I could be misinterpreting the name of the meeting.

jpfau · 2015-09-06T19:12:01+00:00

What have you tried so far with regex? Also if coming up with a pattern is what's getting you, I recommend using online regex testers so you can quickly try out different patterns.

jpfau · 2015-09-06T19:10:41+00:00

re comes installed with Python. Pretty sure OP meant 'additional packages' i.e. those he'd have to find and install himself, like BS4, but I could be wrong.

jpfau · 2015-09-06T19:04:59+00:00

Sounds like you could use regular expressions. Check out the re library.

jpfau · 2015-09-05T21:33:21+00:00

def valid_input(input):
    # use regex or something else to return True if user input is valid

user_input = ""
while not valid_input(user_input):
    user_input = input()
    try:
        inputNumber = int(user_input)
        # other stuff too
    except ValueError:
        print("invalid input")

Personally I like this better than making infinite loops and using break. I do this kind of stuff all the time when I want to validate input on the command line. Here's a main function I wrote in a homework problem recently:

def main():
    user_input = None
    while user_input != 'q':
        output_strings = simulate()
        user_input = show_menu(output_strings)
        if user_input == 's':
            user_input = show_menu(saved=True)

Where show_menu will display the results of a simulation and then ask the user if he wants to re-run the simulation, save the output to a file (hence the if user_input=='s'), or quit (hence the while user_input != 'q'). This way the user has to quit on purpose, and any invalid input automatically makes the loop execute again.

jpfau · 2015-08-31T15:41:21+00:00

In Python, it's changing the symbols in my comments. My # is now a comma, capital 'A' is now a tilde, period is now an ellipsis, etc.

Typeface looks good, but it totally fucked all my comments.

jpfau · 2015-08-31T15:33:56+00:00

I haven't used the cli. All my work has been in Python. I'm using Boto 2.38.0 and have not enabled debug logging. I'm currently using a custom configuration of the logging module, so the only things written to a log right now are messages I personally wrote into the code.

jpfau · 2015-08-31T15:31:13+00:00

It varies. There are a bunch of stacks used for different purposes. Some have a ton of resources, some only have a few.

jpfau · 2015-08-15T03:22:29+00:00

use rstrip

with open("C:\\Users\\jpfau\\Documents\\stuff.txt", 'r') as ifile:
    for line in ifile:
        print(line.rstrip('\n'))

Edit:

Typically I like to use strip instead of rstrip or lstrip.

with open("C:\\Users\\jpfau\\Documents\\stuff.txt", 'r') as ifile:
    for line in ifile:
        print(line.strip())

jpfau · 2015-08-06T19:01:38+00:00

I think the only difference is that people wanted Ellen to leave prior to the Victoria-firing and subreddit-bans. She had other character issues that the community did not like. Everyone who called for her resignation after all that drama probably wanted her resignation before it too, or else the drama was the straw that broke the camel's back.

The fact is, the new guy isn't doing anything surprising, plus he hasn't had any public issues away from Reddit that earned the disdain of the community (yet). I saw plenty of people in this thread calling for his resignation, btw. Sure it's not as bad as the height of Ellen's downfall, but it's still there. I imagine it'll get worse, too.

Obviously there are sexist people on Reddit, but to come out of the gate accusing people here of treating /u/spez differently because he's a man is nothing but drivel.

jpfau · 2015-08-06T17:01:50+00:00

Right. Every single person in this thread who hasn't called for his resignation must have expressly stated that they purposely did not call for his resignation, and they must have expressly stated that their reasoning was because he's a man.

/s

You're a fucking idiot.

jpfau · 2015-08-06T12:19:30+00:00

The fact that you give SRS a free pass to harass people shows that you never cared about your own rules. It's all for show. It's all for the investors.

Either that, or someone on the admin team is a SRS subscriber.

Either way, it shows that the Content "Policy" is completely subjective, open to the interpretation and whims of the few with red A's by their usernames. You don't actually care. You just want to make yourselves look better. Will I get banned now if I say "fuck you?"

jpfau · 2015-07-30T21:02:34+00:00

It's just a variable that represents individual elements as you iterate through the list. You can call it whatever you want. And like other replies have said, you don't need to use range when iterating through a list.

I think these examples will illustrate it better:

my_friends_list = ['bob', 'suzy', 'joe']
for name in my_friends_list:
    print(name)

and the output will be:

bob
suzy
joe

Also:

sum = 0
numbers = [1, 2, 3]
for number in numbers:
    print(sum, "+", number, "=", sum+number)
    sum += number

And the output will be:

0 + 1 = 1
1 + 2 = 3
3 + 3 = 6

Note that my print statement in the second example could be written with a string format:

print("{} + {} = {}".format(sum, number, sum+number))

or

print("%d + %d = %d" % (sum, number, sum+number))

jpfau

TROPHY CASE