what does flask do python code example

Example 1: flask

# This is a basic Flask Tutorial
# First of all, if something doesn't work, you messed up.
# Too start of, make a project folder and install flask with a venv or just normally.
# You can install flask with this command: pip install Flask
# (type this into you're terminal)
# I f you get an error message, it is because you a, dont have python3 installed,
# b: youre on a mac that has Python3 and python2 installed (this is probably the case)
# If you dont have python3 installed then go ahead and install it. If it is case b, then type in
# pip3 install Flask
# Now, lets start by making a file named app.py
# You can return basic html or text when returning in the
# Hello World function. The @app.route('/') defines that the function
# Will return at the page '/'. Debug mode is turned on on and the website
# Will run at 0.0.0.0:5000 aka localhost:5000.

from flask import Flask #Import Flask
from flask import render_template #Import render template function
app = Flask(__name__)


@app.route('/')
def hello_world():
    return '''<h1>Welcome to Flask!</h1><a href=" /about">About Me!</a>'''


# You can also return a Template. For that, make a Templates folder
# and create a file named about.html inside of the Templates folder
# html file contents (copy and paste it without the hashtags):

#<html>
#   <body>
#       <h1>About Me</h1>
#       <p>Hi, this is me, I am a Python programmer who is currently learning Flask!</p>
#       <a href="/">Home</a>
#   </body>
#</html>

# (You can edit it if you want)

#Just for you info, you your Project folder should look like this:
#     ProjectFolder:
#       app.py
#       Templates:
#           about.html
# Lets make a site at localhost:5000/about and use the template we created


@app.route('/about')
def about():
    return render_template("about.html")  # You can do this with every html file in the templates folder

#If you would like to have the same page with 2 diffrent urls (this works with as many as you want)
#You can do this:
@app.route('/page1')
@app.route('/page2')
def page1andpage2():
    return 'Page1 and pag2 are now the same!'
#ps: you dont have to name the function page1andpage2
#you can name every function as you like. It doesn't matter.
#The only thing that matters about the url is the decorator (@app.route('blabla'))
#You can now acces this site on localhost:5000/page1 and on localhost:5000/page2 and they are both the same.

#Since I dont want to make this "Grepper Tutorial" I am prabably going to make a 2cnd part if guys like this




if __name__ == '__main__':
    app.debug = True
    app.run("0.0.0.0", 5000 , debug = True) #If you want to run youre website on a diffrent port,
    #change this number ^

Example 2: flask

from flask import Flask, escape, request

app = Flask(__name__)

@app.route('/')
def hello():
    name = request.args.get("name", "World")
    return f'Hello, {escape(name)}!'