Flask /Basics1

 

Let's start working with flask:

Hello World example in flask.

Lets create our first website using Flask.

The web page will return Hello World.

Make sure you’ve installed Flask

Conda install flask

Pip install flask

Flask is a frame work

Save the file as basic.py

To run the python script in the commend line,

In Terminal, type as:

python basic.py

If your this python file is present in a folder then give the path of the folder.

Click on the link to go the webpage

/information

/puppy/suchitra

When suchitra is passed it will create a web page for suchitra as

This is the page for suchitra.

from flask import Flask
from flask import request
app=Flask(__name__)

@app.route('/puppylatin/<name>')
def PuppyLatin(name):
    if name[-1] != 'y':
        lname = name + 'y'
    else:
        lname = name.replace(name[-1], 'iful')

    return "<h1>Hi {}! Your puppylatin name is {}</h1>".format(name,lname)

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

from flask import Flask
app=Flask(__name__)

@app.route('/') # This is basicalay for home
def index():
   return "<h1> Hello Puppies !</h1>"

@app.route('/NEXTPAGE')
def nextpage():
    return "<h2> To go to next page give the </h2>"

@app.route('/contact')
def contactUs():
    return "<h1> This is contact page </h1>"

#Using dynamic routing.. Here the name will change as u give in the browser
@app.route('/puppy/<name>')
def puppies(name):
    return"<h1>This is the page for {} puppy </h1>".format(name)

# We can five name in any format but to display in uppercase:
@app.route('/profile/<user>')
def Profile(user):
    return "User name in upper case: {}".format(user.upper())

### For debug error: It will return internal server erro. So we cant able to udentify the error
@app.route('/pp/<name>')
def parrot(name):
    return "100th letter: {}".format(name[100])
# Press the green button in the gutter to run the script.
if __name__ == '__main__':
    app.run(debug=True)

Debug Mode:

app.run(debug=True)

Copy the dubbeger pin

Place the pin and Confirm pin

Bebug has 2 main aspects:

Index Error

Flask routing Exercise:

Convert the given puppy name into latin using Flask:

Basic code for Flask Beginners:

Right click on the virtual env folder==> New file==> python file==> Give name:

name_latin_conversion.py and write the basic code.

from flask import Flask
app=Flask (__name__)

@app.route('/')
def index():
    return '<h1> Welcome to my world </h1>'

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

Now save the file and click on Run.

Otherway: python name_latin_conversion.py

Our output appears like this:

Task2: To display the provided by the user

from flask import Flask
app=Flask (__name__)

@app.route('/')
def index():
    return '<h1> Welcome to my world </h1>'
@app.route('/user/<name>')
def convert_name(name):
    return '<h1>User provided name:{}</h1>'.format(name)

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

In the bar we should manually type    /user/any_name

O/p:

Task 3: Converting the user provided name into upper case:

from flask import Flask
app=Flask (__name__)

@app.route('/')
def index():
    return '<h1> Welcome to my world </h1>'
@app.route('/user/<name>')
def convert_name(name):
    return '<h1>Upper case:{}</h1>'.format(name.upper())

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

Task 4: Converting the user name as required format (latin) using if-else condition:

Code:

from flask import Flask
app=Flask (__name__)

@app.route('/')
def index():
    return '<h1> Welcome to my world </h1>'
@app.route('/user/<name>')
def convert_name(name):
    if name[-1]=='y':
        name=name[0:-1]+'iful'
    else:
        name=name+'y'
    return '<h1>Latin :{}</h1>'.format(name)

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

Actual Answer:(Another way)

Output:

Name ending with y:

Name ending without y:

Task 5:

Section 8: Templates:

68. Template Basics:

69. Template Variables

70. Template Control Flow

71. Template Inheritance

72. url_for help function

73.Template forms

74. Flask Template Exercise:

68. Template Basics:

Flask will automatically look for HTML Templates in the templates directory.

Now create a "templates " folder align with basic.py and inside the templates folder create basic.html file

basic.html:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1> Now we entered into html</h1>

</body>
</html>

basic.py

from flask import Flask, render_template
app = Flask(__name__)

@app.route('/')
def index():
    return render_template('basic.html')


# Press the green button in the gutter to run the script.
if __name__ == '__main__':
    app.run()

Output: