# Codecademy: Python

1. Python Syntax

print "Welcome to Python!"
my_int = 7
my_float = 1.23
my_bool = True

my_int = 7
my_int = 3
print my_int

def spam():
    eggs = 12
    return eggs
print spam()

# just a comment
"""
first comment
second comment
third comment
"""

count_to = 1 + 2
count_to = 5 - 2
ni = 2 * 10
ni = 20 / 4
eggs = 10 ** 2
spam = 3 % 2

2. Strings and Console Output

'Help! Help! I\'m being repressed!'

fifth_letter = "MONTY"[4]

parrot = "Norwegian Blue"
print len(parrot)
print parrot.lower()
print parrot.upper()

pi = 3.14
print str(pi)

print "Spam " + "and " + "eggs"
print "The value of pi is around " + str(3.14)

string_1 = "Camelot"
string_2 = "place"
print "Let's not go to %s. 'Tis a silly %s." % (string_1, string_2)

name = raw_input("What is your name?")
quest = raw_input("What is your quest?")
color = raw_input("What is your favorite color?")
print "Ah, so your name is %s, your quest is %s, and your favorite color is %s." % (name, quest, color)

3. Conditionals and Control Flow

# / and * are evaluated before + and -
bool_one = 17 < 118 % 100
bool_two = 100 == (33 * 3) + 1
bool_three = 19 <= 2**4
bool_four = -22 >= -18
bool_five = 99 != 98 + 1

# not is evaluated first, and is evaluated next, or is evaluated last
"""
True and True is True
False or False is False
Not True is False
Not False is True
"""

answer=7
if 5 <= answer:
    print 1
elif answer < 5:
    print -1
else:
    print 0

4. Functions

def square(n):
    """Returns the square of a number."""
    squared = n**2
    print "%d squared is %d." % (n, squared)
    return squared

def favorite_actors(*args):
    """Prints out your favorite actorS (plural!)"""
    print "Your favorite actors are:" , args
favorite_actors("Michael Palin", "John Cleese", "Graham Chapman")

def cube(number):
    return number**3
def by_three(number):
    if number%3 == 0:
        return cube(number)
    else:
        return False
by_three(9)

import math
print math.sqrt(25)
from math import sqrt
print sqrt(25)
from math import *
print sqrt(25)

print max(-10, -5, 5, 10)
print min(-10, -5, 5, 10)
print abs(-10)

print type(42) # => integer
print type(4.2) # => float
print type('spam') # => unicode
print type({'Name':'John Cleese'}) # => dict
print type((1,2)) # => tuple

5. Lists and Dictionaries

zoo_animals = ["pangolin", "cassowary", "sloth", "tiger"]
print zoo_animals[0]

suitcase = []
suitcase.append("sunglasses")
list_length = len(suitcase)

suitcase = ["sunglasses", "hat", "passport", "laptop", "suit", "shoes"]
first = suitcase[0:2]
middle = suitcase[2:4]
last = suitcase[4:6]

animals = "catdogfrog"
cat = animals[:3]
dog = animals[3:6]
frog = animals[6:]

animals = ["aardvark", "badger", "duck", "emu", "fennec fox"]
duck_index = animals.index("duck")
animals.insert(duck_index,"cobra")

my_list = [1,9,3,8,5,7]
for number in my_list:
    print number * 2

start_list = [5, 3, 1, 2, 4]
square_list = []
for number in start_list:
    square_list.append(number**2)
square_list.sort()
print square_list

residents = {'Puffin' : 104, 'Sloth' : 105, 'Burmese Python' : 106}
print residents['Puffin']
print residents['Sloth']
print residents['Burmese Python']

menu = {}
menu['Chicken Alfredo'] = 14.50
menu['Spam'] = 2.50
print "There are " + str(len(menu)) + " items on the menu."
zoo_animals = { 'Unicorn' : 'Cotton Candy House','Rockhopper Penguin' : 'Arctic Exhibit'}
del zoo_animals['Unicorn']
zoo_animals['Rockhopper Penguin'] = 'Anything other'

beatles = ["john","paul","george","ringo","stuart"]
beatles.remove("stuart")

6. Lists and Functions

n = [1, 3, 5]
n.pop(0)

n = [3, 5, 7]
def print_list(x):
    for i in range(0, len(x)):
        print x[i]
print_list(n)

n = [[1, 2, 3], [4, 5, 6, 7, 8, 9]]
def flatten(x):
    r=[]
    for i in x:
        for j in i:
            r.append(j)
    return r
print flatten(n)

7. Loops

while count < 10:
    print "Hello, I am a while and count is", count
    count += 1

choice = raw_input('Enjoying the course? (y/n)')
while choice != 'y' and choice != 'n':
    choice = raw_input("Sorry, I didn't catch that. Enter again: ")

from random import randrange
random_number = randrange(1, 10)
count = 0
while count < 3:
    guess = int(raw_input("Enter a guess:"))
    if guess == random_number:
        print 'You win!'
        break
    count += 1
else:
    print 'You lose.'

for i in range(20):
    print i

word = "eggs!"
for c in word:
    print c

d = {'x': 9, 'y': 10, 'z': 20}
for key in d:
    print key,d[key]

choices = ['pizza', 'pasta', 'salad', 'nachos']
for index, item in enumerate(choices):
    print index+1, item

list_a = [3, 9, 17, 15, 19]
list_b = [2, 4, 8, 10, 30, 40, 50, 60, 70, 80, 90]
for a, b in zip(list_a, list_b):
    print max(a,b)

for i in range(1,10):
    print i
else:
    print i+1

8. Advanced Topics in Python

my_dict = {"Name": "Guido", "Age": 56, "BDFL": True}
print my_dict.items()
print my_dict.keys()
print my_dict.values()
for i in my_dict:
    print i, my_dict[i]

even_squares = [i ** 2 for i in range(1,11) if i ** 2 % 2 == 0]
print even_squares

l = [i ** 2 for i in range(1, 11)]
print l[2:9:2]

my_list = range(1, 11)
print my_list[::2]

to_one_hundred = range(101)
backwards_by_tens = to_one_hundred[::-10]
print backwards_by_tens

languages = ["HTML", "JavaScript", "Python", "Ruby"]
print filter(lambda l: l == "Python", languages)

squares=[i ** 2 for i in range(1,11)]
print filter(lambda s: 30 <= s <= 70, squares)

garbled = "IXXX aXXmX aXXXnXoXXXXXtXhXeXXXXrX sXXXXeXcXXXrXeXt mXXeXsXXXsXaXXXXXXgXeX!XX"
message = filter(lambda g: g != "X" , garbled[::])
print message

9. Introduction to Bitwise Operators

print 5 >> 4  # Right Shift
print 5 << 1  # Left Shift
print 8 & 5   # AND
print 9 | 4   # OR
print 12 ^ 42 # XOR
print ~88     # NOT

print 0b11 * 0b11 # 9

print bin(2) # 0b10

print int("0b11001001", 2) # 201

print bin(0b1110 & 0b101) # 0b100
print bin(0b1110 | 0b101) # 0b1111
print bin(0b1110 ^ 0b101) # 0b1011

def check_bit4(number):
    if number & 0b1000 == 0b1000:
        return "on"
    else:
        return "off"

a = 0b11101110
def flip(number):
    i = 0
    while 2**i-1 < number:
        i+=1
    return number^2**i-1
print bin(flip(a))

10. Introduction to Classes

class ShoppingCart(object):
    items_in_cart = {}
    def __init__(self, customer_name):
        self.customer_name = customer_name
    def add_item(self, product, price):
        if not product in self.items_in_cart:
            self.items_in_cart[product] = price
            print product + " added."
        else:
            print product + " is already in the cart."
    def remove_item(self, product):
        if product in self.items_in_cart:
            del self.items_in_cart[product]
            print product + " removed."
        else:
            print product + " is not in the cart."
my_cart = ShoppingCart("John")
my_cart.add_item("Aquarius",1)

class Employee(object):
    def __init__(self, employee_name):
        self.employee_name = employee_name
    def calculate_wage(self, hours):
        self.hours = hours
        return hours * 20.00
class PartTimeEmployee(Employee):
    def calculate_wage(self, hours):
        self.hours = hours
        return hours * 12
    def full_time_wage(self, hours):
        return super(PartTimeEmployee, self).calculate_wage(hours)
milton = PartTimeEmployee("Milton")
print milton.full_time_wage(10)

11. File Input and Output

my_list = [i**2 for i in range(1,11)]

f = open("output.txt", "w")
for item in my_list:
    f.write(str(item) + "\n")
f.close()

f = open("output.txt", "r")
print f.read()
f.close()

f = open("output.txt", "r")
print f.readline()
print f.readline()
f.close()

with open("text.txt", "w") as my_file:
    my_file.write("Success!")   
print my_file.closed # True