flask setup code example

Example 1: flask install

# install flask (basic, if path is not set yet)
py -m pip install flask
# or set PATH to use pip:
setx PATH "%PATH%;C:\<path\to\python\directory\>\Scripts"
pip install flask
# if "connection error: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed" [!]:
py -m pip install --trusted-host pypi.python.org pip flask
# if PermissionError: [WinError 5] Access is denied
py -m pip install --user flask
# or via creating a virtual environment venv:
py -m venv c:\path\to\new\environment
# then execute:
c:\path\to\new\environment\Scripts\activate.bat

Example 2: install flask

pip install flask

Example 3: install flask

pip install -U Flask

Example 4: flask app example

# Extremely simple flask application, will display 'Hello World!' on the screen when you run it
# Access it by running it, then going to whatever port its running on (It'll say which port it's running on).
from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return 'Hello, World!'

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

Example 5: install flask in venv

$ pip install Flask