# Make a variable to store text
name = "Zach"

# Create variables that are numbers
num_one = 3
num_two = 4
sum_nums = num_one + num_two

# We can also assign multiple variables at once
num_one, num_two = 3, 4

# The value of a variable can be changed after it has been created
num_one = num_one + 1

# The output will be str, or string
print(type(name))

# The output will be int, or integer
print(type(sum_nums))

# The output will be bool, or boolean
print(type(3==3))


# We can change the type of an element by using the shortened name of the type
# We do this when concatenating strings, such as:

age = 16
print("My age is " + str(age))

"""
A multi-line comment describes your code
to someone who is reading it.
"""

Example:

"""
This program will ask the user for two numbers.
Then it will add the numbers and print the final value.
"""
number_one = int(input("Enter a number: "))
number_two = int(input("Enter a second number: "))
print("Sum: " + str(number_one + number_two))

# Use single line comments to clarify parts of code.

Example:

# This program adds 1 and 2
added = 1 + 2
print(added)

# Try/Except with input
try:
    my_number = int(input("Enter an integer: "))
    print("Your number: " + str(my_number))
except ValueError:
    print("That wasn't an integer!")

# Try/Except for Type Errors
try:
    my_number = '2' + 2
except TypeError:
    print("A type error has occurred!")

# Try/Except for Key Errors
dictionary = {'1':'k', '3':'A', '4':'R', '5':'E', '6':'L'}
try:
    dictionary['2']
except KeyError:
    print("Key error")

# Try/Except for Attribute Errors
try:
    dictionary.no_method()
except AttributeError:
    print("Attribute Error!")

# You can also have
try:
    my_number = int(input("Enter an integer: "))
    print("Your number: " + str(my_number))
except:
    print("There was an error.")

# Random integer between (and including) low and high
import random
random_num = random.randint(low, high)
random_element = random.choice(string)

# Example:
# Returns random number within and including 0 and 10.
random_num = random.randint(0,10)

# Random element in a string
random_element = random.choice('abcdefghij')

if BOOLEAN_EXPRESSION:
    print("This executes if BOOLEAN_EXPRESSION evaluates to True")

# Example:

# The text will only print if the user enters a negative number
number = int(input("Enter a number: "))
if number < 0:
    print(str(number) + " is negative!")

if condition_1:
    print("This executes if condition_1 evaluates to True")
elif condition_2:
    print("This executes if condition_2 evaluates to True")
else:
    print("This executes if no prior conditions evaluate to True")

# Example:

# This program will print that the color is secondary
color == "purple"
if color == "red" or color == "blue" or color == "yellow":
    print("Primary color.")
elif color == "green" or color == "orange" or color == "purple":
    print("Secondary color.")
else:
    print("Not a primary or secondary color.")

+   Addition
-   Subtraction
*   Multiplication
/   Division
**  Power
%   Modulus (Remainder)
()  Parentheses (For order of operations)

# Examples
z = x + y
w = x * y

# Division
a = 5.0 / 2                     # Returns 2.5
b = 5.0 // 2                    # Returns 2.0
c = 5/2                         # Returns 2.5
d = 5 // 2                      # Returns 2

# Increment (add one)
x += 1

# Decrement (subtract one)
x -= 1

# Absolute value
absolute_value = abs(x)

abs_val = abs(-5)               # Returns 5

# Square root
import math
square_root = math.sqrt(x)

# Raising to a power
power = math.pow(x, y)          # Calculates x^y
# Alternate
power = x**y                    # Calculates x^y

# Rounding
rounded_num = round(2.675, 2)   # Returns 2.68

x == y      # is x equal to y
x != y      # is x not equal to y
x > y       # is x greater than y
x >= y      # is x greater than or equal to y
x < y       # is x less than y
x <= y      # is x less than or equal to y

# Comparison operators in if statements
if x == y:
    print("x and y are equal")

if x > 5:
    print("x is greater than 5.")

# And Operator
and_expression = x and y

# Or Operator
or_expression = x or y

# You can combine many booleans!
boolean_expression = x and (y or z)

# This for loop will print "hello" 5 times
for i in range(5):
    print("hello")

# This for loop will print out even numbers 1 through 10
for number in range(2, 11, 2):
    print(number)

# This code executes on each item in my_list
# This loop will print 1, then 5, then 10, then 15
my_list = [1, 5, 10, 15]
for item in my_list:
    print(item)

# This program will run as long as the variable 'number' is greater than 0
# Countdown from from 10 to 0
number = 10
while number >= 0:
    print(number)
    number -= 1


# You can also use user input to control a while loop
# This code will continue running while the user answers 'Yes'
answer = input("Continue code?: ")
while answer == "Yes":
    answer = input("Continue code?: ")

# This code will end when the use enters a negative number or 42
number = int(input("Enter a number: "))
while number != 42:
    if number < 0:
        break
    else:
        print(number)
    number = int(input("Enter a number: "))


# This code will only print the numbers 0 to 3 and 6
for i in range(5):
    if i < 4:
        print(i)
    else:
        continue
print(6)

def name_of_your_function():
    # Code that will run when you make a call to
    # this function.

# Example:

# Teach the computer to add two numbers
num_one = 1
num_two = 2
def add_numbers():
    sum_nums = num_one + num_two

# We add a return statement in order to use the value of the sum variable
num_one = 1
num_two = 2
def add_numbers():
    sum_nums = num_one + num_two
    return sum_nums

# Call the add_numbers() function once
# The computer will return a value of 3
add_numbers()

# Call the add_numbers() function 3 times and print the output
# The output will be the number 3 printed on 3 separate lines
print(add_numbers())
print(add_numbers())
print(add_numbers())

# In this program, parameters are used to give two numbers
def add_numbers(num_one, num_two):
    sum_nums = num_one + num_two
    return sum_nums

# We call the function with values inside the parentheses
# This program will print '7'
print(add_numbers(3, 4))
# If we have a list with the same number of parameters, we
# can use the items to assign arguments using an asterisk
my_list = [3, 4]
print(add_numbers(*my_list))

# Prints a character at a specific index
my_string = "hello!"
print(my_string[0])       # print("h")
print(my_string[5])       # print("!")

# Prints all the characters after the specific index
my_string = "hello world!"
print(my_string[1:])      # print("ello world!")
print(my_string[6:])      # prints("world!")

# Prints all the characters before the specific index
my_string = "hello world!"
print(my_string[:6])     # print("hello")
print(my_string[:1])     # print("h")

# Prints all the characters between the specific indices
my_string = "hello world!"
print(my_string[1:6])      # print("ello")
print(my_string[4:7])      # print("o w")

# Get the length of the string
print(len(my_string))

# Iterates through every character in the string
# Will print one letter of the string on each line in order
my_string = "Turtle"
for i in range(len(my_string)):
    print(my_string[i])

# Another way to iterate through each character in the string
my_string = "Turtle"
for letter in my_string:
    print(letter)

# Completes commands if the string is found inside the given string
my_string = "hello world!"
if "world" in my_string:
   print("world")

# Concatenation
my_string = "Tracy the"
print(my_string + " turtle")    # print("Tracy the turtle")

# Splits the string into a list of letters
my_string = "Tracy"
my_list = list(my_string)       # my_list = ['T', 'r', 'a', 'c', 'y']

# Using enumerate will print the index number followed by a colon and the
# word at that index for each word in the list
my_string = "Tracy is a turtle"
for index, word in enumerate(my_string.split()):
    print(str(index) + ": " + word)

# upper: To make a string all uppercase
my_string = "Hello"
my_string = my_string.upper()     # returns "HELLO"

# lower: To make a string all lowercase
my_string = "Hello"
my_string = my_string.lower()     # returns "hello"

# isupper: Returns True if a string is all uppercase letters and False otherwise
my_string = "HELLO"
print(my_string.isupper())        # returns True

# islower: Returns True if a string is all lowercase letters and False otherwise
my_string = "Hello"
print(my_string.islower())         # returns False

# swapcase: Returns a string where each letter is the opposite case from original
my_string = "PyThOn"
my_string = my_string.swapcase()  # returns "pYtHoN"

# strip: Returns a copy of the string without any whitespace at beginning or end
my_string = "       hi there       "
my_string = my_string.strip()     # returns "hi there"

# find: Returns the lowest index in the string where substring is found
# Returns -1 if substring is not found
my_string = "eggplant"
index = my_string.find("plant")   # returns 3
index = my_string.find("Tracy")   # returns -1

# split: Splits the string into a list of words at whitespace
my_string = "Tracy is a turtle"
my_list = my_string.split()       # Returns ['Tracy', 'is', 'a', 'turtle']

# Make a new tuple named "my_tuple"
my_tuple = (1, 2, 3, 4, 5)

# Tuple with elements of different types
my_tuple = (0, 1, "Tracy", (1, 2))

# Tuple with single element
my_tuple = (3,)

# Tuple of tuples
my_tuple((0, 1), (2, 3))

# Get the length of the tuple
print(len(my_tuple))

# Accessing elements within nested tuples
print(my_tuple[0][0])
print(my_tuple[1][0])

# Concatenating tuples
x = (1, 2)
y = (5, 6)
my_tuple = x + (3,) + y

# Create an empty list
my_list = []

# Create a list with any number of items
my_list = [item1, item2, item3]
# Example:
number_list = [1, 2, 4]

# A list can have any type
my_list = [integer, string, boolean]
# Example:
a_list = ["hello", 4, True]

# Access an element in a list using indexing
a_list = ["hello", 4, True]
first_element = a_list[0]    # Returns "hello"

# Access multiple elements in a list using slicing
a_list = ["hello", 4, True]
first_element = a_list[0:2]    # Returns ["hello", 4]

# Set an element in a list
a_list = ["hello", 4, True]
a_list[0] = 9                # Changes a_list to be [9, 4, True]

# Looping over a list
# Prints each item on a separate line (9, then 4, then True)
a_list = [9, 4, True]
for item in a_list:
    print(item)

# Length of a list
a_list = [9, 4, True]
a_list_length = len(a_list)  # Returns 3

# Creates a list based on first operation
# This will create a list with numbers 0 to 4
a_list = [x for x in range(5)]
# This will create a list with multiples of 2 from 0 to 8
list_of_multiples = [2*x for x in range(5)]

# append: Add to a list
a_list = ["hello", 4, True]
a_list.append("Puppy")       # Now a_list = ["hello", 4, True, "Puppy"]

# pop: Remove and return last element from the list
a_list = ["hello", 4, True]
last_item = a_list.pop()     # Removes True, now a_list = ["hello", 4]
# Remove and return an item from a list at index i
a_list = ["hello", 4, True]
a_list.pop(0)                # Removes "hello", now a_list = [4, True]

# index: Returns the index value of the first item in the list that matches element
# There is an error if there is no such item
a_list = ["hello", 4, True]
a_list.index(4)               # Returns 1 because 4 is found at index[1]
a_list.index("hi")            # Error because no item "hi"

# sort: Sorts a given list
my_list = [9, 7, 1, 2, 3]
my_list.sort()               # Sorts list to [1, 2, 3, 7, 9]

# reverse: Reverses a given list
my_list = [1, 2, 3, 4]
my_list.reverse()            # Reverses list to [4, 3, 2, 1]

# count: Returns the number of instances of a particular item that were found
my_list = [1, 4, 2, -4, 10, 0, 4, 2, 1, 4]
print(my_list.count(4))       # Returns 3
print(my_list.count(123))     # Returns 0 because 123 does not exist in list

# extend: Allows us to add a list to a list
my_list = [1, 2, 3]
my_list.extend([4, 5, 6])    # Returns [1, 2, 3, 4, 5, 6]

# remove: Allows us to remove a particular item from a list
# Only removes the first instance of the item
my_list = ["apple", "banana", "orange", "grapefruit"]
my_list.remove("orange")     # Returns ["apple", "banana", "grapefruit"]


# join: Creates string out of list with specified string placed between each item
my_list = ["Tracy", "is", "a", "turtle"]
(" ").join(my_list)          # Returns the list as a string with spaces between words

# Create an empty list
my_list = []

# Add to the list
my_list.append([1, 2, 3])
my_list.append([4, 5, 6])

# Access elements within the nested lists
print(my_list[0])       # Returns [1, 2, 3]
print(my_list[0][1])    # Returns 2

# Take a slice of the outer list
print(my_list[0:2])     # Returns [[1, 2, 3], [4, 5, 6]]

# Take a slice of the inner list
print(my_list[0][0:2])  # Returns [1, 2]

a_dictionary = {key1:value1, key2:value2}
# Example:
my_farm = {pigs:2, cows:4}  # This dictionary keeps a farm's animal count

# Creates an empty dictionary
a_dictionary = {}

# Inserts a key-value pair
a_dictionary[key] = value
my_farm["horses"] = 1      # The farm now has one horse

# Gets a value for a key
my_dict[key] # Will return the key
my_farm["pigs"]            # Will return 2, the value of "pigs"

# Using the 'in' keyword
my_dict = {"a": 1, "b": 2}
print("a" in my_dict)       # Returns True
print("z" in my_dict)       # Returns False
print(2 in my_dict)        # Returns False, because 2 is not a key

# Iterating through a dictionary
for key in my_dict:
    print("key: " + str(key))
    print("value: " + str(my_dict[key]))

# Declare a class
class MyClass:
    # The __init__ method is called whenever we instantiate our class
    def __init__(self):
        print("Class initiated")
        self.my_num = 0

# Instantiate your class
my_class = MyClass()

# Access instance variables in your class
print(my_class.my_num)

my_class.my_num = 10

# Adding arguments to your class
class Point:
    def __init__(self, x = 0, y = 0):
        self.x = x
        self.y = y

# Instantiate the class
p = Point(3, 4)

# Make a new set named "new_set"
new_set = set([])
girl_scout_badges = set([])

# Add to a set
new_set.add(item)
girl_scout_badges.add("Squirrel Whisperer")

# Does a set contain a value
item in my_set # Returns a boolean
"Squirrel Whisperer" in girl_scout_badges  # Returns True

# Number of elements in the set
len(my_set)
len(girl_scout_badges)  # Returns 1 since there is only one item in the set

print("Hello world")
print(2 + 2)
print(10)

name = "Tracy"
age = 13
print("My name is " + name + " and I am " + str(age) + " years old!")

print("My name is %s and I am %d years old!" % ('Zara', 21))

# Ask the user for input and save it to a variable to be used in code
# This will only work if the input is being used as a string
name = input("What is your name? ")

# If input needs to be used as a number (i.e for a mathematical
# calculation), include the term 'int' or 'float'
num_one = int(input("Enter a number: "))
num_two = int(input("Enter a second number: "))
num_three = float(input("Enter a third number: "))

# This input can then be used to control different parts of the code
print("Hello, " + name)
sum_nums = num_one + num_two

# Extracting Data from a File:

# Example File:

#        test.txt
#   ------------------
#
#   Hello World
#   This is File Input
#
#   ------------------

# Opening the file, Create a File object and store it in a Variable:
file = open('test.txt')

# Getting all text:
file.read()     # Returns:
                #   Hello World
                #   This is File Input

# Getting a Line of Text:
file.readline()     # Returns:
                    #   Hello World

# Getting lines in a file:
for line in file:
    print(line + '!')   # prints:
                        #   Hello World\n!
                        #   This is File Input\n!

# Note '\n', signifying the end of a line of text
for line in file:
    print(line + '!')    # prints:
                        #   Hello World
                        #   !
                        #   This is File Input
                        #   !

# To remove this extra newline, we can use:
for line in file:
    print(line.strip() + '!')   # prints:
                                #   Hello World!
                                #   This is File input!

# Closing a File
file.close()