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I am trying write discord bots using Python, I have come across and threw together this bot.

import discord
import asyncio
import random

client = discord.Client()
inEmail = input("Email:")
inPassword = input("Passwd:")

async def background_loop():
    await client.wait_until_ready()
    while not client.is_closed:
        channel = client.get_channel("************")
        messages = ["Hello!", "How are you doing?", "Testing!!"]
        await client.send_message(channel, random.choice(messages))
        await asyncio.sleep(120)

client.loop.create_task(background_loop())
client.run(inEmail, inPassword)

Yet when I tried to run it, I received a SyntaxError:

File "1.py", line 7
  async def background_loop():
     ^
SyntaxError: invalid syntax

Why is that? I have never received that before when I tested it.

Asynchronous requests were introduced to Python in v3.3, if you're running Python prior to v3.3 (including v2.X), you'll have to install a newer version of Python.


Only if you are running Python 3.3: asyncio is not part of the stdlib, you'll need to install it manually from pypi:

pip install asyncio

The async and await keywords are only valid for Python 3.5 or newer. If you're using Python 3.3 or 3.4, you will need to make the following changes to your code:

  1. Use the @asyncio.coroutine decorator instead of the async statement:

async def func():
    pass

# replace to:

@asyncio.coroutine
def func():
    pass
  1. Use yield from instead of await:

await coroutine() 

# replace to:

yield from coroutine()

Here is an example of what your function need to change into (if you're on 3.3-3.4):

import asyncio

@asyncio.coroutine 
def background_loop():
    yield from client.wait_until_ready()
    while not client.is_closed:
        channel = client.get_channel("************")
        messages = ["Hello!", "How are you doing?", "Testing!!"]
        yield from client.send_message(channel, random.choice(messages))
        yield from asyncio.sleep(120)

The aforementioned syntax is still supported in newer versions of Python 3, but it is recommended to use await and async if there's no need to support for Python 3.3-3.4. You can refer back to this documentation, here's a short snippet:

The async def type of coroutine was added in Python 3.5, and is recommended if there is no need to support older Python versions.


Aside:

discord.py currently supports 3.4.2-3.6.6, (It does not support 3.3-3.4.1, 3.7 as of January 2019).

For developing with discord.py, I suggest using the discord.py rewrite branch:

discord.py-rewrite supports 3.5.3-3.7.

Python3 flagging 'async def' as invalid syntax, I believe async and await are for python 3.5, I think you'll need to use the @ asyncio.coroutine decorator for async def and yield from for await in python 3.4. As tobyd's answer points out, async and await aren't supported until Python 3.5, but the question says that Python 3.4 is installed. Running python3 <yourbot>.py will just run the Python 3.4 version which doesn't work, unfortunately.

From version 3.7 async and await are reserved keywords

like the error in below image.

Copy and open the path (without __init__.py). You will get a list of .py files

Rename async.py to _async.py or anything you want, as async is now a reserved keyword with us from version 3.7.

Once renamed, modify the new name everywhere.

*NOTE Although it is not a permanent solution but it worked for me in case of the same syntax error while working with firebase. Best solution is to go with previous version of Python. i.e version below 3.7.

SyntaxError for 'async def' � Issue #597 � google/yapf � GitHub, A SyntaxError is raised when formatting our Main.py which looks like Main.py", line 44 async def on_ready(): ^ SyntaxError: invalid syntax. The async def type of coroutine was added in Python 3.5, and is recommended if there is no need to support older Python versions. Aside: discord.py currently supports 3.4.2-3.6.6, (It does not support 3.3-3.4.1, 3.7 as of July, 2018). In the near future, they are planning to raise the minimum Python version to 3.5.3.

I solved it by installing the updated PyMC from github (they corrected the bug that happens in Python 3.7):

pip install git+https://github.com/pymc-devs/pymc.git

How do I code a Discord Bot in Python on an Iphone or Chromebook , File "<stdin>", line 7 async def on_ready(): ^ SyntaxError: invalid syntax Unknown Error. This is insanely frustrating… can someone assist? (i am� I'm currently developing some async python in vim and have pymode installed as a plugin. But I'm having an issue with file linting because the linter gets hung up on the first (and valid) async definition and won't lint the rest of the file.

PEP 492 -- Coroutines with async and await syntax, It is a SyntaxError to use await outside of an async def function (like it is a SyntaxError to use yield outside of def Invalid syntax examples:� In versions of Python before 3.6, the interpreter doesn’t know anything about the f-string syntax and will just provide a generic "invalid syntax" message. The problem, in this case, is that the code looks perfectly fine, but it was run with an older version of Python.

Back to the future with async and await in Python 3.5, I think I first heard about attempt to include new syntax for asynchronous programs around Being at the top of release notes does not necessarily mean that the feature is a big change await asyncio.sleep(3) ^ SyntaxError: invalid syntax. Async/await. The newer and cleaner syntax is to use the async/await keywords. Introduced in Python 3.5, async is used to declare a function as a coroutine, much like what the @asyncio.coroutine decorator does. It can be applied to the function by putting it at the front of the definition: async def ping_server(ip): # ping code here

18.5.3. Tasks and coroutines — Python 3.6.3 documentation, The async def type of coroutine was added in Python 3.5, and is recommended if Generator-based coroutines use the yield from syntax introduced in PEP 380, instead of the If the future's result isn't yet available, raises InvalidStateError . Declaring async def noop(): pass is valid: Using await and/or return creates a coroutine function. To call a coroutine function, you must await it to get its results. It is less common (and only recently legal in Python) to use yield in an async def block. This creates an asynchronous generator, which you iterate over with async for.

Comments
  • Using async before a function definition is only valid syntac in Python 3.4 or greater.
  • Yes I have been running the script using "python3 1.py"
  • I see, so anything above python 3.4 should work? That is really strange since my server changed python versions somehow over night :P