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I am trying to get a function to run asynchronously in my Flask application in Python3.x. I am using the asyncio library and have put async outside of my function declaration, but I am getting an error that reads:
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1997, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1985, in wsgi_app
response = self.handle_exception(e)
File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1540, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python3.6/site-packages/flask/_compat.py", line 33, in reraise
raise value
File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1982, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1615, in full_dispatch_request
return self.finalize_request(rv)
File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1630, in finalize_request
response = self.make_response(rv)
File "/usr/local/lib/python3.6/site-packages/flask/app.py", line 1740, in make_response
rv = self.response_class.force_type(rv, request.environ)
File "/usr/local/lib/python3.6/site-packages/werkzeug/wrappers.py", line 885, in force_type
response = BaseResponse(*_run_wsgi_app(response, environ))
File "/usr/local/lib/python3.6/site-packages/werkzeug/test.py", line 884, in run_wsgi_app
app_rv = app(environ, start_response)
TypeError: 'coroutine' object is not callable
My code is as follows:
import asyncio
... more function definitions ...
@app.route("/save_to_dbx")
@login_required
async def save_to_dbx():
""" Saves a course to Dropbox as a .zip """
# Creating a .zip file out of the course
zip = zipfile.ZipFile("IoT.zip", "w")
for subdir, dirs, files in os.walk(os.path.join(BASE_PATH, "static/Content/IoT")):
for file in files:
complete__file_path = os.path.join(subdir, file)
print("Writing to Zip:", complete__file_path)
zip.write(complete__file_path, complete__file_path.split("/")[-1])
zip.close()
# Uploading the .zip to Dropbox
f = open(os.path.join(BASE_PATH, "IoT.zip"))
file_size = os.path.getsize(os.path.join(BASE_PATH, "IoT.zip"))
CHUNK_SIZE = 4 * 1024 * 1024
print("Upload file size:", file_size)
if file_size <= CHUNK_SIZE:
print(__dbx_conn__().files_upload(f, "/VOSW-Backup-Testing/IoT.zip"))
else:
upload_session_start_result = __dbx_conn__().files_upload_session_start(f.read(CHUNK_SIZE))
cursor = dropbox.files.UploadSessionCursor(
session_id=upload_session_start_result.session_id,
offset=f.tell())
commit = dropbox.files.CommitInfo(path="/VOSW-Backup-Testing/IoT.zip")
while f.tell() < file_size:
if ((file_size - f.tell()) <= CHUNK_SIZE):
print(__dbx_conn__().files_upload_session_finish(f.read(CHUNK_SIZE), cursor, commit))
else:
__dbx_conn__().files_upload_session_append_v2(f.read(CHUNK_SIZE), cursor)
cursor.offset = f.tell()
return """<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Success!</title>
</head>
<body>
<h1>Success!</h1>
</body>"""
What is causing this error?
832
flask is not asynchronous. It is not directly compatible with asyncio at all, and passing a async function to @app.route in a flask application won't work.
I suggest using quart instead.
144
You should consider using Sanic. It is really fast and handles async requests very well.
with sanic you can consider this solution.
45
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