>>> sign = "+"                                  

>>> my_list = ["One", "Two", "Three", "Four"]   

>>> new_string = sign.join(my_list)      
>>> new_string

'One+Two+Three+Four'

>>> my_string = "unjustified text"                        # Create a String

>>> new_string = my_string.ljust(2*len(my_string), "X")   # left justify, fit within 2*len of string, fill with X

>>> new_string                                      

'unjustified textXXXXXXXXXXXXXXXX'

>>> my_string = "sTrInG mEtHoDs"               # Create a String

>>> new_string = my_string.lower()             # Return the lowercased string

>>> new_string                                 # Check to see what was returned   

'string methods'

>>> my_string = "sTrInG mEtHoDs"                # Create a string

>>> new_string = my_string.capitalize()         # Capitalize 1st, lower rest & return

>>> new_string                            

'String methods'

>>> my_string = "sTrInG mEtHoDs"               # Create a String

>>> new_string = my_string.casefold()          # Return a casefolded copy

>>> new_string                              

'string methods'

>>> my_string = "sTrInG mEtHoDs"               # Create a String

>>> new_string = my_string.center(20, 'x')     # Center in 20 spaces, fill spaces with 'x' & return

>>> new_string                             

'xxxsTrInG mEtHoDsxxx'

>>> my_string = "this is python. It is awesome!"     # Create a String

>>> my_count = my_string.count('is', 0, -1)          # count occurrences of'is' and return

>>> my_count                                    

3

>>> my_string = "we love python"              # Create a String

>>> my_value = my_string.endswith('python')   # Return a boolean

>>> my_value                        

True

>>> my_string = "we love python"        # Create a String

>>> my_index = my_string.find('o')      # Return the lowest index where substring was found

>>> my_index                          

4

>>> a = 10       

>>> b = 30       
>>> my_sum = a + b
>>> my_product = a * b

>>> "The sum of a and b is {0} and their product is {1}".format(my_sum, a*b)

'The sum of a and b is 40 and their product is 300'

>>> my_string = "we love python"        # Create a String

>>> my_index = my_string.index('o')     # Return lowest index at which the substring was found 

>>> my_index                            # Check to see what was returned   

4

>>> my_string_1 = "StarWars2016"              # Notice there is no space
>>> my_string_2 = "I love star wars 2016"     # This string contains spaces

>>> check_1 = my_string_1.isalnum()           # Returns a Boolean value
>>> check_2 = my_string_2.isalnum()           # Returns a Boolean value

>>> "check_1 is: {0} and check_2 is: {1}".format(check_1, check_2)   # Check to see what was returned   

'check_1 is: True and check_2: is False'

my_list = ["Tom", "Henry", "Mickey", "Juliet", "Sophie"]    # Create a List

my_list.append("William")                                   # Append "William" to the end of the list

print(my_list)   

['Tom', 'Henry', 'Mickey', 'Juliet', 'Sophie', 'William']

list_one = [1, 2, 3, 4, 5, 6, 7]                          # This is the first list
list_two = [10, 12, 14]                                   # This is the second list

list_one.extend(list_two)                                 # Extend list_one by appending all items of list_two

print(list_one)                         

[1, 2, 3, 4, 5, 6, 7, 10, 12, 14]

my_list = ["Tom", "Henry", "Mickey", "Juliet", "Sophie"]    # Create a List

my_list.insert(1, "Siddhartha")                             # Insert the string "Siddhartha" at index 1

print(my_list)                                   

['Tom', 'Siddhartha', 'Henry', 'Mickey', 'Juliet', 'Sophie']

my_list = ["Thou", "art", "precious!", "art", "gracious"]     # Create a list
my_list.remove("art")                                         # Remove the first occurrence of the string "art"
print(my_list)

['Thou', 'precious!', 'art', 'gracious']

my_list = ["Thou", "art", "precious!", "art", "gracious"]        # Create a list
my_item = my_list.pop(2)                                         # Remove item at index 2 and return it
print("The item that was popped was: ", my_item)                 # Print my_item to see what was returned
print("my list now looks like = ", my_list)

The item that was popped was:  precious!

my list now looks like =  ['Thou', 'art', 'art', 'gracious']

my_list = [2, 3, 5, 7, 11, 13]                                # Create a list
my_list.clear()                                               # Remove all the items from the list
print(my_list) 

[]

my_list = ["Python", "is", "awesome", "Java", "is", "Alright"]       # Create a list
my_index = my_list.index("is")                                       # Return the index of the first "is"
print("The item was first found at index:", my_index)

The item was first found at index: 1

my_list = ["mew", "mew", "kitten", "mew", "mew"]                  # Create a list
my_count = my_list.count("mew")                                   # Return the number of times "mew" appears
print("The number of times the item appeared was:", my_count)  

The number of times the item appeared was: 4

my_list = [5, 3, 6, 1, 2, 4, 7]                  # Create a list
my_list.sort()                                   # Sort the items of the list in place
print("Sorted list looks like:", my_list)

Sorted list looks like: [1, 2, 3, 4, 5, 6, 7]

my_list = ["zero", "one", "two", "three", "four", "five"]        # Create a list
my_list.reverse()                                                # Reverse the items of the list in place
print("Reversed list looks like:", my_list)

Reversed list looks like: ['five', 'four', 'three', 'two', 'one', 'zero']

original_list = ["zero", "one", "two", "three"]        # Create a list
copied_list = original_list.copy()                     # Copy the original list and return it.       
print("Copied list looks like:", copied_list) 

Copied list looks like: ['zero', 'one', 'two', 'three']

my_value = -11.55                             # Notice that my_value is a negative floating point number

absolute = abs(my_value )                     # Return the absolute value

print("The absolute value is:", absolute) 

The absolute value is: 11.55

my_list = ["abs", "len", 1, 2, "many", "more to come"]      # Create a list called "my_list"

my_size = len(my_list)                                      # Return length (the number of items) of my_list

print("The length of my_list is:", my_size)

The length of my_list is: 6

my_list = [-10, 12, 111, 32.3, 0, 4, 24]                        # Create a list called "my_list"

my_mx1 = max(my_list)                                          # Return the largest item in my_list

my_max2 = max(my_list[0], my_list[-1])                          # Return the largest among first & last element
print("The largest item of my_list is:", my_max1)               # Print my_max1 to see what was returned

print("The larger among first and last item is:", my_max2)

The largest item of my_list is: 111

The larger among first and last item is: 24

my_list = [10, -12, 11, 32.3, 1, 14, -5]                         # Create a list called "my_list"

my_min1 = min(my_list)                                           # Return the smallest item in my_list

my_min2 = min(my_list[0], my_list[-1])                           # Return the smallest among first & last element

print("The smallest item of my_list is:", my_min1)               # Print my_min1 to see what was returned

print("The smaller among first and last item is:", my_min2)

The smallest item of my_list is: -12

The smaller among first and last item is: -5

x = 5                                                   # initialize a variable x

y = 3                                                   # initialize a variable y

result = pow(x, y)                                      # Return x to the power of y. Same as x**y

print("The result of the operation is", result)

The result of the operation is 125

# Lets sort the following list by the first item in each sub-list.
my_list = [[2, 4], [0, 13], [11, 14], [-14, 12], [100, 3]]
# First, we need to define a function that specifies what we would like our items sorted by
def my_key(item):

    return item[0]                                            # Make the first item in each sub-list our key
new_sorted_list = sorted(my_list, key=my_key)                 # Return a sorted list as specified by our key
print("The sorted list looks like:", new_sorted_list)       

The sorted list looks like: [[-14, 12], [0, 13], [2, 4], [11, 14], [100, 3]]