ImportError: cannot import name 'Flask' from 'flask' (unknown location)

[Shubham-Kumar-2000]

I am trying to deploy a simple application using zappa which uses flask and moviepy.

Context

Neither the name of the folder nor the any file is named as flask.
Locally python ./app.py is just working fine.
I am running on python 3.9

Expected Behavior

To run normally on lambda.

Actual Behavior

When trying to do zappa deploy every thing works fine except it ends with a 502.
Then when tried to debugged with zappa tail dev, found this :

Instancing..
[1639313514980] Failed to find library: libmysqlclient.so.18...right filename?
[1639313515099] [ERROR] ImportError: cannot import name 'Flask' from 'flask' (unknown location)
Traceback (most recent call last):
  File "/var/task/handler.py", line 657, in lambda_handler
    return LambdaHandler.lambda_handler(event, context)
  File "/var/task/handler.py", line 251, in lambda_handler
    handler = cls()
  File "/var/task/handler.py", line 148, in __init__
    self.app_module = importlib.import_module(self.settings.APP_MODULE)
  File "/var/lang/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 850, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "/tmp/transcripter/app.py", line 1, in <module>
    from flask import Flask, render_template, request, redirect

Steps to Reproduce

1. zappa deploy
2. zappa tail dev

Your Environment

• Zappa version used: 0.54.1
• Operating System and Python version: Windows 10 with python 3.9
• The output of pip freeze:

certifi==2021.10.8
charset-normalizer==2.0.9
click==8.0.3
colorama==0.4.4
decorator==4.4.2
Flask==2.0.2
Flask-Cors==3.0.10
idna==3.3
imageio==2.13.3
imageio-ffmpeg==0.4.5
itsdangerous==2.0.1
Jinja2==3.0.3
MarkupSafe==2.0.1
moviepy==1.0.3
numpy==1.21.4
Pillow==8.4.0
proglog==0.1.9
requests==2.26.0
six==1.16.0
SpeechRecognition==3.8.1
tqdm==4.62.3
urllib3==1.26.7
Werkzeug==2.0.2

• Your zappa_settings.json:

{
    "dev": {
        "app_function": "app.app",
        "profile_name": null,
        "aws_region": "ap-south-1",
        "project_name": "transcripter",
        "runtime": "python3.9",
        "s3_bucket": "zappa-e5ola6g1j",
        "slim_handler": true,
        "include": []
    }
}

And additionally I don't understand why this Failed to find library: libmysqlclient.so.18...right filename? keeps coming.

[Shubham-Kumar-2000]

If I just disable the slim_handler :
I get a different error :

Runtime.ImportModuleError: Unable to import module 'handler': attempted relative import with no known parent package
Traceback (most recent call last):

[RobbenRibery]

same error