# This is a comment
# These lines of code will not change any values
# Anything following the first # is not run as code

""" This is a special string """

' This is a special string '

my_integer = 50
print(my_integer, type(my_integer))

50 <class 'int'>

one = 1
print(One)

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-4-6b74af782f90> in <module>
      1 one = 1
----> 2 print(One)

NameError: name 'One' is not defined

my_float = 1.0
print(my_float, type(my_float))
my_float = float(1)
print(my_float, type(my_float))

1.0 <class 'float'>
1.0 <class 'float'>

my_int = int(3.14159)
print(my_int, type(my_int))

3 <class 'int'>

my_string = 'This is a string with single quotes'
print(my_string)
my_string = "This is a string with double quotes"
print(my_string)

This is a string with single quotes
This is a string with double quotes

my_string = '"Jabberwocky", by Lewis Carroll'
print(my_string)
my_string = "'Twas brillig, and the slithy toves / Did gyre and gimble in the wabe;"
print(my_string)

"Jabberwocky", by Lewis Carroll
'Twas brillig, and the slithy toves / Did gyre and gimble in the wabe;

my_bool = True
print(my_bool, type(my_bool))

True <class 'bool'>

print('Addition:', 2 + 2)
print('Subtraction:', 7 - 4)
print('Multiplication:', 2 * 5)
print('Division:', 10 / 2)
print('Exponentiation:', 3**2)

Addition: 4
Subtraction: 3
Multiplication: 10
Division: 5.0
Exponentiation: 9

print('Modulo:', 15 % 4)

Modulo: 3

first_integer = 4
second_integer = 5
print(first_integer * second_integer)

20

import math

print('Pi:', math.pi)
print("Euler's Constant:", math.e)

Pi: 3.141592653589793
Euler's Constant: 2.718281828459045

print('Cosine of pi:', math.cos(math.pi))

Cosine of pi: -1.0

my_list = [1, 2, 3]
print(my_list)

[1, 2, 3]

print(my_list[0])
print(my_list[2])

1
3

print('The first, second, and third list elements:', my_list[0], my_list[1], my_list[2])
print('Accessing outside the list bounds causes an error:', my_list[3])

The first, second, and third list elements: 1 2 3

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
<ipython-input-18-b7c80acbca97> in <module>
      1 print('The first, second, and third list elements:', my_list[0], my_list[1], my_list[2])
----> 2 print('Accessing outside the list bounds causes an error:', my_list[3])

IndexError: list index out of range

print(len(my_list))

3

print(my_list)
my_list[0] = 42
print(my_list)

[1, 2, 3]
[42, 2, 3]

my_string = "Strings never change"
my_string[0] = 'Z'

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-21-85065ecd61ab> in <module>
      1 my_string = "Strings never change"
----> 2 my_string[0] = 'Z'

TypeError: 'str' object does not support item assignment

my_list_2 = ['one', 'two', 'three']
print(my_list_2)

['one', 'two', 'three']

my_list_3 = [True, 'False', 42]

my_list_4 = my_list + my_list_2 + my_list_3
print(my_list_4)

[42, 2, 3, 'one', 'two', 'three', True, 'False', 42]

my_list = ['friends', 'romans', 'countrymen', 'lend', 'me', 'your', 'ears']

print(my_list[2:4])

['countrymen', 'lend']

print(my_list[1:])

['romans', 'countrymen', 'lend', 'me', 'your', 'ears']

print(my_list[:4])

['friends', 'romans', 'countrymen', 'lend']

print(my_list[-1])

ears

print(my_list[0:7:2])

['friends', 'countrymen', 'me', 'ears']

print(my_list[::2])

['friends', 'countrymen', 'me', 'ears']

print(my_list[:])

['friends', 'romans', 'countrymen', 'lend', 'me', 'your', 'ears']

print(my_list[::-1])

['ears', 'your', 'me', 'lend', 'countrymen', 'romans', 'friends']

b = 10
my_list = range(b)
print(list(my_list))

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

a = 0
b = 10
my_list = range(a, b)
print(list(my_list))

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

a = 0
b = 10
step = 2
my_list = range(a, b, step)
print(list(my_list))

[0, 2, 4, 6, 8]

my_tuple = 'I', 'have', 30, 'cats'
print(my_tuple)

('I', 'have', 30, 'cats')

my_tuple = ('I', 'have', 30, 'cats')
print(my_tuple)

('I', 'have', 30, 'cats')

my_tuple[3] = 'dogs' # Attempts to change the 'cats' value stored in the the tuple to 'dogs'

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-39-c821a6bdb1a6> in <module>
----> 1 my_tuple[3] = 'dogs' # Attempts to change the 'cats' value stored in the the tuple to 'dogs'

TypeError: 'tuple' object does not support item assignment

print(my_tuple[1:3])

('have', 30)

my_other_tuple = ('make', 'that', 50)
print(my_tuple + my_other_tuple)

('I', 'have', 30, 'cats', 'make', 'that', 50)

str_1, str_2, int_1 = my_other_tuple
print(str_1, str_2, int_1)

make that 50

things_i_like = {'dogs', 7, 'the number 4', 4, 4, 4, 42, 'lizards', 'man I just LOVE the number 4'}
print(things_i_like, type(things_i_like))

{4, 7, 'dogs', 'lizards', 42, 'man I just LOVE the number 4', 'the number 4'} <class 'set'>

animal_list = ['cats', 'dogs', 'dogs', 'dogs', 'lizards', 'sponges', 'cows', 'bats', 'sponges']
animal_set = set(animal_list)
print(animal_set) # Removes all extra instances from the list

{'bats', 'dogs', 'lizards', 'sponges', 'cats', 'cows'}

print(len(animal_set))

6

'cats' in animal_set # Here we check for membership using the `in` keyword.

True

print(animal_set | things_i_like) # You can also write things_i_like | animal_set with no difference

{'bats', 4, 7, 'dogs', 'lizards', 'sponges', 42, 'cats', 'cows', 'man I just LOVE the number 4', 'the number 4'}

print(animal_set & things_i_like) # You can also write things_i_like & animal_set with no difference

{'dogs', 'lizards'}

my_dict = {"High Fantasy": ["Wheel of Time", "Lord of the Rings"], 
           "Sci-fi": ["Book of the New Sun", "Neuromancer", "Snow Crash"],
           "Weird Fiction": ["At the Mountains of Madness", "The House on the Borderland"]}

print(my_dict["Sci-fi"])

['Book of the New Sun', 'Neuromancer', 'Snow Crash']

my_dict["Sci-fi"] = "I can't read"
print(my_dict["Sci-fi"])

I can't read

my_dict["Historical Fiction"] = ["Pillars of the Earth"]
print(my_dict["Historical Fiction"])

['Pillars of the Earth']

print(my_dict)

{'High Fantasy': ['Wheel of Time', 'Lord of the Rings'], 'Sci-fi': "I can't read", 'Weird Fiction': ['At the Mountains of Madness', 'The House on the Borderland'], 'Historical Fiction': ['Pillars of the Earth']}

first_string = '"Beware the Jabberwock, my son! /The jaws that bite, the claws that catch! /'
second_string = 'Beware the Jubjub bird, and shun /The frumious Bandersnatch!"/'
third_string = first_string + second_string
print(third_string)

"Beware the Jabberwock, my son! /The jaws that bite, the claws that catch! /Beware the Jubjub bird, and shun /The frumious Bandersnatch!"/

my_string = 'Supercalifragilisticexpialidocious'
print('The first letter is:', my_string[0]) # Uppercase S
print('The last letter is:', my_string[-1]) # lowercase s
print('The second to last letter is:', my_string[-2]) # lowercase u
print('The first five characters are:', my_string[0:5]) # Remember: slicing doesn't include the final element!
print('Reverse it!:', my_string[::-1])

The first letter is: S
The last letter is: s
The second to last letter is: u
The first five characters are: Super
Reverse it!: suoicodilaipxecitsiligarfilacrepuS

print('Count of the letter i in Supercalifragilisticexpialidocious:', my_string.count('i'))
print('Count of "li" in the same word:', my_string.count('li'))

Count of the letter i in Supercalifragilisticexpialidocious: 7
Count of "li" in the same word: 3

print('The first time i appears is at index:', my_string.find('i'))

The first time i appears is at index: 8

print("All i's are now a's:", my_string.replace('i', 'a'))

All i's are now a's: Supercalafragalastacexpaaladocaous

print("It's raining cats and dogs".replace('dogs', 'more cats'))

It's raining cats and more cats

my_string = "I can't hear you"
print(my_string.upper())
my_string = "I said HELLO"
print(my_string.lower())

I CAN'T HEAR YOU
i said hello

my_string = "{0} {1}".format('Marco', 'Polo')
print(my_string)

Marco Polo

my_string = "{1} {0}".format('Marco', 'Polo')
print(my_string)

Polo Marco

print('insert %s here' % 'value')

insert value here

print('There are %s cats in my %s' % (13, 'apartment'))

There are 13 cats in my apartment

print(5 == 5)

True

print(5 > 5)

False

m = 2
n = 23
print(m < n)

True

statement_1 = 10 > 2
statement_2 = 4 <= 6
print("Statement 1 truth value: {0}".format(statement_1))
print("Statement 2 truth value: {0}".format(statement_2))
print("Statement 1 and Statement 2: {0}".format(statement_1 and statement_2))

Statement 1 truth value: True
Statement 2 truth value: True
Statement 1 and Statement 2: True

print(((2 < 3) and (3 > 0)) or ((5 > 6) and not (4 < 2)))

True

# Similar to how float() and int() work, bool() forces a value to be considered a boolean!
print(bool(''))

False

print(bool('I have character!'))

True

print(bool([]))

False

print(bool([1, 2, 3]))

True

# This is the basic format of an if statement. This is a vacuous example. 
# The string "Condition" will always evaluated as True because it is a
# non-empty string. he purpose of this code is to show the formatting of
# an if-statement.
if "Condition": 
    # This block of code will execute because the string is non-empty
    # Everything on these indented lines
    print(True)
else:
    # So if the condition that we examined with if is in fact False
    # This block of code will execute INSTEAD of the first block of code
    # Everything on these indented lines
    print(False)
# The else block here will never execute because "Condition" is a non-empty string.

True

i = 4
if i == 5:
    print('The variable i has a value of 5')

i = 4
if i == 5:
    print("All lines in this indented block are part of this block")
    print('The variable i has a value of 5')
else:
    print("All lines in this indented block are part of this block")
    print('The variable i is not equal to 5')

All lines in this indented block are part of this block
The variable i is not equal to 5

i = 1
if i == 1:
    print('The variable i has a value of 1')
elif i == 2:
    print('The variable i has a value of 2')
elif i == 3:
    print('The variable i has a value of 3')
else:
    print("I don't care what i is")

The variable i has a value of 1

i = 10
if i % 2 == 0:
    if i % 3 == 0:
        print('i is divisible by both 2 and 3! Wow!')
    elif i % 5 == 0:
        print('i is divisible by both 2 and 5! Wow!')
    else:
        print('i is divisible by 2, but not 3 or 5. Meh.')
else:
    print('I guess that i is an odd number. Boring.')

i is divisible by both 2 and 5! Wow!

i = 5
j = 12
if i < 10 and j > 11:
    print('{0} is less than 10 and {1} is greater than 11! How novel and interesting!'.format(i, j))

5 is less than 10 and 12 is greater than 11! How novel and interesting!

my_string = "Carthago delenda est"
if my_string == "Carthago delenda est":
    print('And so it was! For the glory of Rome!')
else:
    print('War elephants are TERRIFYING. I am staying home.')

And so it was! For the glory of Rome!

if 'a' in my_string or 'e' in my_string:
    print('Those are my favorite vowels!')

Those are my favorite vowels!

i = 5
while i > 0: # We can write this as 'while i:' because 0 is False!
    i -= 1
    print('I am looping! {0} more to go!'.format(i))

I am looping! 4 more to go!
I am looping! 3 more to go!
I am looping! 2 more to go!
I am looping! 1 more to go!
I am looping! 0 more to go!

for i in range(5):
    print('I am looping! I have looped {0} times!'.format(i + 1))

I am looping! I have looped 1 times!
I am looping! I have looped 2 times!
I am looping! I have looped 3 times!
I am looping! I have looped 4 times!
I am looping! I have looped 5 times!

my_list = {'cats', 'dogs', 'lizards', 'cows', 'bats', 'sponges', 'humans'} # Lists all the animals in the world
mammal_list = {'cats', 'dogs', 'cows', 'bats', 'humans'} # Lists all the mammals in the world
my_new_list = set()
for animal in my_list:
    if animal in mammal_list:
        # This adds any animal that is both in my_list and mammal_list to my_new_list
        my_new_list.add(animal)
        
print(my_new_list)

{'bats', 'dogs', 'cats', 'cows', 'humans'}

i = 10
while True:
    if i == 14:
        break
    i += 1 # This is shorthand for i = i + 1. It increments i with each iteration.
    print(i)

for i in range(5):
    if i == 2:
        break
    print(i)

0
1

i = 0
while i < 5:
    i += 1
    if i == 3:
        continue
    print(i)

for i in range(5):
    loop_string = 'I transcend the loop!'
    print('I am eternal! I am {0} and I exist everywhere!'.format(i))

print('I persist! My value is {0}'.format(i))
print(loop_string)

I am eternal! I am 0 and I exist everywhere!
I am eternal! I am 1 and I exist everywhere!
I am eternal! I am 2 and I exist everywhere!
I am eternal! I am 3 and I exist everywhere!
I am eternal! I am 4 and I exist everywhere!
I persist! My value is 4
I transcend the loop!

my_dict = {'firstname' : 'Inigo', 'lastname' : 'Montoya', 'nemesis' : 'Rugen'}

for key in my_dict:
    print(key)

firstname
lastname
nemesis

for key in my_dict:
    print(my_dict[key])

Inigo
Montoya
Rugen

for key, value in my_dict.items():
    print(key, ':', value)

firstname : Inigo
lastname : Montoya
nemesis : Rugen

def hello_world():
    """ Prints Hello, world! """
    print('Hello, world!')

hello_world()

Hello, world!

for i in range(5):
    hello_world()

Hello, world!
Hello, world!
Hello, world!
Hello, world!
Hello, world!

def see_the_scope():
    in_function_string = "I'm stuck in here!"

see_the_scope()
print(in_function_string)

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-95-fb168f245f67> in <module>
      3 
      4 see_the_scope()
----> 5 print(in_function_string)

NameError: name 'in_function_string' is not defined

def free_the_scope():
    in_function_string = "Anything you can do I can do better!"
    return in_function_string
my_string = free_the_scope()
print(my_string)

Anything you can do I can do better!

def multiply_by_five(x):
    """ Multiplies an input number by 5 """
    return x * 5

n = 4
print(n)
print(multiply_by_five(n))

4
20

def calculate_area(length, width):
    """ Calculates the area of a rectangle """
    return length * width

l = 5
w = 10
print('Area:', calculate_area(l, w))
print('Length:', l)
print('Width:', w)

Area: 50
Length: 5
Width: 10

def calculate_volume(length, width, depth):
    """ Calculates the volume of a rectangular prism """
    return length * width * depth

def sum_values(*args):
    sum_val = 0
    for i in args:
        sum_val += i
    return sum_val

print(sum_values(1, 2, 3))
print(sum_values(10, 20, 30, 40, 50))
print(sum_values(4, 2, 5, 1, 10, 249, 25, 24, 13, 6, 4))

6
150
343

def test_args(*args):
    print(type(args))

test_args(1, 2, 3, 4, 5, 6)

<class 'tuple'>

def has_a_vowel(word):
    """ 
    Checks to see whether a word contains a vowel 
    If it doesn't contain a conventional vowel, it
    will check for the presence of 'y' or 'w'. Does
    not check to see whether those are in the word
    in a vowel context.
    """
    vowel_list = ['a', 'e', 'i', 'o', 'u']
    
    for vowel in vowel_list:
        if vowel in word:
            return True
    # If there is a vowel in the word, the function returns, preventing anything after this loop from running
    return False

my_word = 'catnapping'
if has_a_vowel(my_word):
    print('How surprising, an english word contains a vowel.')
else:
    print('This is actually surprising.')

How surprising, an english word contains a vowel.

def point_maker(x, y):
    """ Groups x and y values into a point, technically a tuple """
    return x, y

a = point_maker(0, 10)
b = point_maker(5, 3)
def calculate_slope(point_a, point_b):
    """ Calculates the linear slope between two points """
    return (point_b[1] - point_a[1])/(point_b[0] - point_a[0])
print("The slope between a and b is {0}".format(calculate_slope(a, b)))

The slope between a and b is -1.4

print("The slope-intercept form of the line between a and b, using point a, is: y - {0} = {2}(x - {1})".format(a[1], a[0], calculate_slope(a, b)))

The slope-intercept form of the line between a and b, using point a, is: y - 10 = -1.4(x - 0)

P	Q	`not` P	P `and` Q	P `or` Q
`True`	`True`	`False`	`True`	`True`
`False`	`True`	`True`	`False`	`True`
`True`	`False`	`False`	`False`	`True`
`False`	`False`	`True`	`False`	`False`

Introduction to Python¶

Code Comments¶

Variables¶

Basic Math¶

Collections¶

Lists¶

Slicing¶

Tuples¶

Sets¶

Dictionaries¶

String Shenanigans¶

String Formatting¶

Logical Operators¶

Basic Logic¶

Truthiness¶

If-statements¶

Loop Structures¶

Functions¶

Next Steps¶