Web Dev Bootcamp TIL Day-8(Python Basics/ Flask Review/ Git Crash Course)

Python Basics

map(function, iterable)

• map() function returns a map object(which is an iterator) of the results after applying the given function to each item of a given iterable (list, tuple etc.)

lambda argument: expression

• anonymous function
• lambda arg : expression
• ex) square = lambda x : x **2 ----> stores function inside square()

filter(function, iterable)

• return values from the iterable that are True when evaluated by the function

#Program to filter out only the even items from a list
my_list = [1, 5, 4, 6, 8, 11, 3, 12]
new_list = list(filter(lambda x: (x%2 == 0) , my_list))
print(new_list)

 

function(*args)

• takes in all arguments

function(**kwargs)

• creates dictionary

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Flask Review

#import Flask class from flask module
from flask import Flask

#create an instance of the Flask class
#save the application object in a variable called app
app = Flask(__name__)

• When creating a Flask object, we need to pass in the name of the application. In this case, because we are working with a single module, we can use the special Python variable, __name__.

@app.route('/')
@app.route('/home')
#both http://localhost:5000/ and http://localhost:5000/home
def hello_world():
    return <h1>'Hello World!'</h1>
#will return the h1 header Hello World

• route -----> return a response function

 

We can use triple quotes to contain multi-line code:

@app.route('/')
@app.route('/home')
def home():
    return '''
    <h1>Hello, World!</h1>
    <p>My first paragraph.</p>
    CODECADEMY
    '''

 

We can use an anchor tag with href = ... route name to create a truncated hyperlink

@app.route('/reporter')
def reporter():
    return '''
    <h2>Reporter Bio</h2>
    #anchor tag that creates a link back to homepage
    <a href="/">Return to home page</a>
    '''

 

Dynamic URLS

@app.route('/orders/<user_name>/<int:order_id>')
def orders(user_name, order_id):
    return f'<p>Fetching order #{order_id} for {user_name}.</p>'

@app.route('/article/<article_name>')
def article(article_name):
  return f'''
  <h2>{article_name.replace('-', ' ').title()}</h2>
  <a href='/'>Return back to home page</a>
  '''