#This is a comment. Use comments to describe code # You can uncomment chunks using Cmd (or Ctrl) + /

x = 5 #int v = 2.0 #float z = False #bool y = "Hello World" #string #You can also initialize multiple comma-separated variables at once: a,b,c = 1,2,3 # Creates the three variables a,b,c, and assigns them values 1,2,3, respectively

print(x) print(v,z,y) # You can print multiple comma-separated values at once

x = 5+3-2 print(x) x = 7*6/2 #print(x) # Order of operations is enforced, and parentheses are supported x = (5+3)*2 / 4 #print(x) # Exponentiation is supported with the (**) operator x = 2**3 #print(x) # Other built-in operators are the modulo operator (%), which calculated the 'remainder' of division between two values... x = 17%4 #print(x) #... as well as the floor division operator (//), which gives the result of divison between two values rounded down to the nearest integer. x = 17//4 #print(x,y)

x = 5.0 #print(x) x += 3 # Update the value of x by adding 3 #print(x) x /= 2 # Update the value of x by dividing 2 #print(x) # You can also use the variable itself in an update expression in Python. x = 5.0 x = x + x*x #print(x)

x = 5.0 # print(x == 5) # print(x < 5) # print(x <= 5) # print(not(x <= 5)) # print(not(x == 10)) #A common pitfall is to confuse = (an assignment operator) with == (a Boolean operator). Don't do this! # = is used to initialize variables # == is used to compute whether or not two variables are equal. y = 3.0 # print((y == 50.) or ( x== 5.0)) # print((y == 50.) and ( x== 5.0)) # print(not((y == 50.) and ( x== 5.0))) # print(not((y == 3.0) or ( x== 5.0))) # print(True == False)

x = [1, 2, 3, 4, 5] #This is a list #print(len(x)) #print(x[0]) #print(x[-1]) #print(x[0:2]) #print(x[0:4:2]) #print(3 in x) #print(7 in x) # You can mutate lists in-place x.append(6) #print(x) x.remove(4) #print(x) x[3] = 7 #print(x) #You can also use lists that contain other lists. The number of nested lists can be thought of as a 'dimension'. # Uncomment each line of code below, and provide a brief commented explanation of what each line does: y = [[1, 2], [3, 4], [5, 6]] #This is a 2-D list #print(len(y)) #print(y[0]) #print(y[0][0]) #print(y[1:3][0:2]) # You will find that we will use large, multidimensional lists/arrays (i.e. matrices and tensors) frequently in machine learning.

x = [1.0, 2.0, 3.0, 4.0, 5.0] y = 6 print(x*y)

x = [1.0, 2.0, 3.0, 4.0, 5.0] counter = 0 # Start with index 0 while counter < len(x): # As long as we're working with an index found in x x[counter] *= 6 # Multiply the element at the counter index by 6 counter += 1 # Iterate the counter so that we move to the next index on our next pass through this code block. print(x) # Notice that the block of code has stopped executing now that the counter has reached a value of 5; # at this point the conditional in the 'while' loop is no longer true and the indented block of code stops running. print(counter)

x = [1.0, 2.0, 3.0, 4.0, 5.0] new_x = [] # Initialize an empty list to hold our new values for i in x: # For all of the elements 'i' in list x: new_x.append(i * 6) # Multiply the element by 6 and add it to the new list. print(new_x)

x = [1.0, 2.0, 3.0, 4.0, 5.0] for i in range(len(x)): # For all indices in list x x[i] *= 6 # Mutate the element at that index by multiplying it with 6 print(x)

x = [1.0, 2.0, 3.0, 4.0, 5.0] x = [y*6 for y in x] #x is the list of each element 'y' of x multiplied by 6 print(x) # The tradeoff here is between code readability and compactness

a = [10.0, 11.0, 12.0, 13.0, 14.0, 15.0] b = [4.0, 3.0, 5.0, 6.0, 4.0, 3.0] # While Loop: # For loop: #(Challenge) List comprehension:

x = 5 # if (x % 2 == 0): # print("x is even") # else: # print("x is odd") y = 3 # if (x > y): # print("x is greater than y") # elif (x < y): # print("x is less than y") # else: # print("x is equal to y")

# Write your code here:

def sum(list_to_sum): """Finding the sum of all the elements in a list Args: list_to_sum: The list whose elements will be summed over Returns: list_sum: the total sum of the list """ list_sum = 0 for i in list_to_sum: list_sum += i return list_sum #Verify that this function works x = [1, 2, 3, 4] y = [5, 6, 7, 8] z = [2, 4, 6, 8] w = [1, 3, 5, 7] # print(sum(x)) # print(sum(y)) # print(sum(z)) # print(sum(w))

#Write your function here: #Test the funtion here: print(my_control_flow_fn(2)) print(my_control_flow_fn(3.0)) print(my_control_flow_fn("Hello!")) print(my_control_flow_fn(True)) print(my_control_flow_fn([1,2,3,4]))

def greet(name="Shriram", time_of_day="morning"): """Prints a greeting Args: name: A string indicatnig the name to gree time_of_day: A string indicating the time of day """ print("Hello, " + name + ". Good " + time_of_day + "!") greet() # This will run the generic arguments greet(time_of_day="evening") #If we want to change a generic argument, we state it ths way greet(name="Andy") greet(name="Professor Rotskoff", time_of_day="afternoon") # You can mix and match generic arguments with arguments that always require user input as well.

#Write the function here: #Test the function here a = [10.0, 11.0, 12.0, 13.0, 14.0, 15.0] b = [4.0, 3.0, 5.0, 6.0, 4.0, 3.0] print(list_subtraction_fn(a,b))

class Animal(): #Notice the standard documentation for classes is similar to that of functions """Defines an Animal Attributes: species: A string indicating the species type position: A list indicating the x and y positions of the animal """ #We initialize the value of all of the class attributes in the __init__ function (i.e. the "constructor") #This function is run automatically whenever a new class object is created. def __init__(self, species="monkey"): self.species=species #Use 'self' to self-reference the object. In this case, we tell the object, once created, to set its own species attribute. self.position = [0, 0] #Class functions often change the attributes of the object somehow #Here, we define two class functions that change the position attribute of our animal def move_vertical(self, amount = 1): # The first argument to class functions is always 'self' """Moves function vertically by amount Args: amount: distance to move vertically by """ self.position[1] += amount def move_horizontal(self, amount = 1): """Moves function horizontally by amount Args: amount: distance to move horizontally by """ self.position[0] += amount #Let's create a dog and move it around! a = Animal("dog") print(a.species) a = Animal() # This Animal object will have the generic species, since we didn't pass one as an argument print(a.species) print(a.position) a.move_vertical() print(a.position) a.move_horizontal() print(a.position)

class Dog(Animal): """Defines a Dog which subclasses Animal Attributes: name: A string indicating the name of the dog """ def __init__(self, name="Buster"): super().__init__(species="dog") #We need to call the constructor of the 'super' (more general) class when we create a new subclass self.name = name #We then take care of the assignment of the attributes specific to this subclass def bark(self): print("Bark!") d = Dog() print(d.species) print(d.position) d.move_vertical() print(d.position) d.move_horizontal() print(d.position) print(d.name) d.bark()

import numpy

print(sqrt(4))

print(np.sqrt(4))

x = np.array([1.0, 2.0, 3.0, 4.0, 5.0]) y = x*6 print(y)

# Write your function here: #Test the function here a = np.array([10.0, 11.0, 12.0, 13.0, 14.0, 15.0]) b = np.array([4.0, 3.0, 5.0, 6.0, 4.0, 3.0]) print(array_subtraction_fn(a,b))