Issues Encountered While Setting Up Flask and Resolving Dependency Conflicts

Code Help Python
1

Subject: Issues Encountered While Setting Up Flask and Resolving Dependency Conflicts

Question:

Description: Hello Replit Community … While attempting to integrate Flask into an existing Python project, I encountered several issues related to the Replit environment’s configuration and dependency management, which have disrupted the normal functioning of the project.

  1. Issues with Flask Setup I created an app.py file and attempted to run a basic Flask app. However, I am unable to run the Flask app due to errors related to the python3 command not being found, despite having Python 3.9 installed in the environment.
  2. Issues with poetry and python3 Command To resolve the Flask setup issue, I attempted to add Flask via poetry. However, I encountered errors stating multiple versions of poetry were found in Nix, and even after selecting a version, I received compatibility errors due to the Python version being 3.9.6, while the project required >=3.10.0,<3.11.
  3. Issues with replit.nix and Dependency Management Attempts to resolve the aforementioned issues by modifying replit.nix resulted in Nix errors, particularly related to poetry being a top-level attribute. Modifications to the .replit file to run app.py also resulted in errors stating that the python3 command is not found.
  4. Project Disruption The project was functioning normally before attempts to integrate Flask and resolve the subsequent issues. Now, running the main file results in errors, and even modules like numpy are not being recognized.

Specific Errors:

  • ModuleNotFoundError: No module named 'flask'
  • python3: command not installed. Multiple versions of this command were found in Nix.
  • The currently activated Python version 3.9.6 is not supported by the project (>=3.10.0,<3.11).
  • error: poetry was promoted to a top-level attribute, use poetry-core to build Python packages
  • ModuleNotFoundError: No module named 'numpy'

Request: I would like assistance in resolving the aforementioned issues, particularly:

  • Guidance on properly setting up Flask in the Replit environment.
  • Resolution of the python3 command not found issue.
  • Clarification on managing Python versions and dependencies using poetry in Replit, and resolution of the compatibility errors.
  • Assistance in resolving Nix errors related to replit.nix modifications.
  • Restoration of the project’s normal functioning and resolving module recognition issues like with numpy.

Code:
replit.nix

{ pkgs }: {
  deps = [pkgs.python39Packages.poetry
pkgs.python39Full
pkgs.mailutils
  ];
}

app.py

from flask import Flask, render_template, request

app = Flask(__name__)

@app.route('/', methods=['GET', 'POST'])
def index():
    if request.method == 'POST':
        question = request.form.get('question')
        # Here we will handle the user's question and return the answer
        # For now, just return the question as is
        return f'You asked: {question}'
    return render_template('index.html')

if __name__ == '__main__':
    app.run(debug=True)

poetry.toml

[tool.poetry]
name = "python-template"
version = "0.1.0"
description = ""
authors = ["Your Name <you@example.com>"]

[tool.poetry.dependencies]
python = "^3.9"
feedparser = "^6.0.10"
openai = "^0.28.0"
pypdf2 = "^3.0.1"
pytube = "^15.0.0"
requests = "^2.31.0"
spacy = "^3.6.1"
sumy = "^0.11.0"
bs4 = "^0.0.1"
en-core-web-sm-mirror = "2.2.5"
Flask = "^2.0.1"
numpy = "^1.26.0"
[tool.poetry.dependencies]
python = "^3.9"


[tool.pyright]
# https://github.com/microsoft/pyright/blob/main/docs/configuration.md
useLibraryCodeForTypes = true
exclude = [".cache"]

[tool.ruff]
# https://beta.ruff.rs/docs/configuration/
select = ['E', 'W', 'F', 'I', 'B', 'C4', 'ARG', 'SIM']
ignore = ['W291', 'W292', 'W293']

[build-system]
requires = ["poetry-core>=1.0.0"]
build-backend = "poetry.core.masonry.api"
2

Hi @TimCoyne , welcome to the forums!
To install numpy or flask, try this:

pip install --upgrade pip
pip install numpy
pip install flask

Remove all the extra stuff from replit.nix to look like this:

{ pkgs }: {
  deps = [
  ];
}

Does it work?

2 Likes
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Flask Replit template

2 Likes
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@NateDhaliwal … thank you so much for the help!

Removing all the extra stuff from replit.nix helped me at least get back to a working state, albeit without the Flask implementation. But it was definitely a life saver. I’m back to square one with Flask, which is exactly where I was hoping to be. Thank you!!!

With respect to the pip installs, numpy & flask were already installed, but I received an odd message when i tried to upgrade pip. Any insight?

pip: command not installed. Multiple versions of this command were found in Nix.
Select one to run (or press Ctrl-C to cancel):
> 
python39Packages.pip.out
python39Packages.bootstrapped-pip.out
python38Packages.pip.out
python38Packages.bootstrapped-pip.out
5

thank you, @QwertyQwerty88 !!

6

I assume all of your questions were or are solved, so please mark one of their answers as the solution since both worked.

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@NateDhaliwal … With respect to the pip installs … I received an odd message when i tried to upgrade pip.

Any insight?

pip: command not installed. Multiple versions of this command were found in Nix.
Select one to run (or press Ctrl-C to cancel):
> 
python39Packages.pip.out
python39Packages.bootstrapped-pip.out
python38Packages.pip.out
python38Packages.bootstrapped-pip.out
8

Hi @TimCoyne , welcome to the forums!
Can you try pip install pip?
If that doesn’t work, try what is said in this post:

9

Hello, try this:
Show hidden files and open .replit file, then replace the contents with the following:

entrypoint = "main.py"
modules = ["python-3.10:v18-20230807-322e88b"]

hidden = [".pythonlibs"]

[nix]
channel = "stable-23_05"

[deployment]
run = ["python3", "main.py"]
deploymentTarget = "cloudrun"

Reload the shell. This will probably solve the pip and poetry problems. You may need to reinstall your packages with poetry install or upm install. Also, it will run Python 3.10 instead of 3.9.

2 Likes
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