first_name = "ada"
last_name = "lovelace"
full_name = f"{first_name} {last_name}" # this is called a format string or f-string older Pythons use format() methods instead ex full_name = {} {}.format(first_name, last_name) 
print(full_name)

`import this` -> The Zen of Python 
1. Beautiful is better than ugly.
2. Simple is better than complex.
3. Complex is better than complicated.
4. Readability counts.
5. There should be one and preferably one obvious way to do it.
6. Now is better than never.

for i in range(4):
    for j in range(5):
        print(i, j)

## here for every iteration of i all the iterations of j will work
#so when i = 0, j will assume all values from 0 to 4

squares = [] # we created an empty list
for value in range(1, 6): #here value variable assumes a value through 1 to 5 one by one.
	square = value ** 2 #another variable square is defined which should be equal to the square of every iteration of value variable. 
	squares.append(square) #above square values is added to the list squares
print(squares) #list is printed

#shorted version of above program
squares = []
for value in range(1,6):
	squares.append(value**2) #argument added to append() method
print(squares)

# admin list and if-else statements sample program to check if list is empty or not.

usernames = ['admin', 'swet91', '123username', 'myusername', 'swetsagar']

if usernames : #first if statement when usernames list is not empty.
	for username in usernames : 
		if username == 'admin' : 
			print(f"Hello {username}, would you like to have a status report.")
		else :
			print(f"Hello {username}, thank you for logging in again.")
else : # when usernames list is empty
	print("We need to find some users.")	

# loopoing through dictionaries

dictionary_0 =  {'a' : 1 , 'b' : 2 , 'c' : 3 ,} 

for alphabet, number in dictionary_0.items() :
	print(alphabet, end = " ")
	print(number)
# for printing values through keys
for key in dictionary_0 : 
	print(dictionary_0[key])

# nested list in a dictionary

favorite_places = {
	'Superman' : ['Detroit', 'New York',],
	'Ironman' : ['Michigan', 'Bangalore', 'New Delhi'],
	'Hulk' : ['Rachenahalli', 'Main Road'],
}

for name, places in favorite_places.items() :
	print(f"Hello, {name} your favorite places are")
	for place in places : #this is an important line.
		print(f"{place}")

#prgram to print natural numbers from 1 to 10 using while loop
current_number = 1
while current_number <= 1 : ## this is called a conditional statement
	print(current_number)
	current_number += 1.

# running until user write Quit
prompt_exit = "I repeat what you write. Write something."
prompt_exit += "Enter quit to exit the program."
message = "" #empty string defined for while loop to check something first time it runs

while message != 'quit' : 
	message = input(prompt_exit)
	print(message) 

#using while and continue to print odd numbers
starting_digit = 1

while starting_digit <= 10 :
	starting_digit += 1
	if current_number %2 == 0:
		continue
	print(starting_digit)

# adding items to new list using while loop
unconfirmed_users = [ 'alice', 'brin', 'candice']
confirmed_users = []

while unconfirmed_users : # **IMPORTANT** it means the while loop will run as long as the list is not empty
	current_user = unconfirmed_users.pop() # removes unverified users one at a time from the end
	print(f"verifying user : {current_user}") 
	confirmed_users.append(current_user) # adding confirmed users into a new list

print("confirmed user list is : ") 
for confirmed_user in confirmed_users : # printing users from the confirmed users list.
	print(confirmed_user)

# filling dictionary with user input
polling_active = True # flag variable 
responses = {} # empty dictionary to store responses

while polling_active : # condition until flag variable is True
	name = input("what is your name? ") # 1st input for dictionary (key)
	response = input("name a mountain peak you wish to climb") #2nd input (value)

	responses[name] = response # function to store responses to dictionary

	# Below is to find if more polls are to be taken or end program

	repeat = input(" Would you like to let another person respond? (yes/no)")
	if repeat == 'no' : 
		polling_active = False

# printing contents of dictionary 
print("Poll results") 
for name, response in responses.items() : 
	print(f"{name} would like to climb {response}")

# greet user function
def greet_user(username) : # defining the function using 'def' keword 
	## within the parentheses it holds info 
	print(f"hello, {username.title()}") # body of the function 

greet_user('Batman') # calling the functions

#making a dictionary from user input using function and while loops.

def make_album(artist_name, album_title) : 
	album_detail = {'Name of Artist' : artist_name, 'Title of album : ' : album_title}
	for name, title in album_detail.items() : 
		print(name, end = " ")
		print(title)

while True : 
	artist_name = input("Please enter a name or q to quit.")
	if artist_name == 'q' : 
		break
	
	album_title = input("Please enter album title or q to quit.")
	if album_title == 'q' : 
		break 
	
	make_album(artist_name, album_title)

#passing a list in a function

def greet_user(names) : 
	for name in names : 
		print(f"Hello, {name.title()}")
usernames = ['a', 'b', 'c'] # passing a list to a function to print
greet_user(usernames) # greeting a specific set of users

class Dog : # class called dog

	def __init__(self, name, age) : ##__init__ special method that runs we create a new instance based on Dog class
		## name, age are instance attributes
		self.name = name 
		self.age = age 

	def sit(self) : 
		print(f"{self.name} is now sitting")

	def roll_over(self) :
		print(f"{self.name} rolled over")

#creating instances from a Class
my_dog = Dog('suzie', '6')

print(f"My dog's name is {my_dog.name}")
print(f"My dog is {my_dog.age} years old")

#accessing attributes Dot(.) notation is used

print(my_dog.name)
print(my_dog.age)

# calling methods instance_name.method()
my_dog.sit()
my_dog.roll_over()

# creating another instance/ multiple instances.
your_dog = Dog('lucy', 5)
print(f"Your dogs name is {your_dog.name}")
print(f"Your dogs age is {your_dog.age}")
your_dog.sit()
your_dog.roll_over()

def update_odometer(self, mileage) :
		self.odometer_reading = mileage

# child class example
class ElectricCar(Car) : # ElectricCar is the child class/subclass 
	def __init__(self, make, model, year) : 
		super().__init__(make, model, year) # super() used to call method from parent class/superclass
		self.battery_size = 75

	def describe_battery(self) : 
		print(f"This car has a {self.battery_size} Kwh battery.")	

my_tesla = ElectricCar('tesla', 'model s', 2019) # we are creating a new object called my_tesla from class Car with the attributes make, model, year
# this my_tesla here refers to self above
print(my_tesla.get_descriptive_name())
my_tesla.describe_battery()

with open('pi_digits.txt') as file_object:
    contents = file_object.read()
print(contents)

try:
	print(5/0) #if this code would have worked Py would have skipped except block
except ZeroDivisionError:
	print("not possible")

# sample program to find number of words in a text
filenames = ['siddhartha.txt']
for file in filenames:
	try:
		with open(file, encoding='utf-8') as f:
			content = f.read()
			print(content)
			words = content.split()  # content that is one big string is split into a list of words
			# len() funtion is used to find total words from that list of words
			num_words = len(words)
			print(num_words)
	except FileNotFoundError:
		print(f'File {f} is missing')

import json

numbers = [2, 3, 5, 7, 11, 13]
filename = 'numbers.json'

with open(filename, 'w') as f : 
    json.dump(numbers, f) 

import json

filename = 'numbers.json'

with open(filename) as f : 
    numbers = json.load(f) 

print(numbers)

# take an input from user save it in a file and bring it out when run again.
import json

filename = 'numbers.json'

try : 
    with open(filename) as f :
        fav_number = json.load(f)

except : 
    fav_number = int(input("Enter your favorite number : "))
    with open(filename, 'w') as f : 
        fav_number = json.dump(fav_number, f)
    print('Okay, number saved.')

else : 
    print(f"Your favorite number is {fav_number}.")
    

if __name__ == '__main__'
	unittest.main()