WEEK-4

Assessment 7 problem 1

## Create a function called mult that has two parameters, the first is required and should be an integer, the second is an optional parameter that can either be a number or a string but whose default is 6. The function should return the first parameter multiplied by the second.
def mult(a,b=6):
    return a*b

Assessment 7 problem 2

## def greeting(greeting="Hello ", name, excl="!"):
    return greeting + name + excl

print(greeting("Bob"))
print(greeting(""))
print(greeting("Bob", excl="!!!"))

Need to change-
def greeting(name, greeting="Hello ",excl="!"):

Assessment 7 problem 3

## Below is a function, sum, that does not work. Change the function definition so the code works. The function should still have a required parameter, intx, and an optional parameter, intz with a defualt value of 5.

def sum(intz=5, intx):
    return intz + intx
    
   
def sum(intx,intz=5):
    return intz + intx

Assessment 7 problem 4

Write a function, test, that takes in three parameters: a required integer, an optional boolean whose default value is True, and an optional dictionary, called dict1, whose default value is {2:3, 4:5, 6:8}. If the boolean parameter is True, the function should test to see if the integer is a key in the dictionary. The value of that key should then be returned. If the boolean parameter is False, return the boolean value “False”.

def test(a,b=True,dict1={2:3, 4:5, 6:8}):
    if b == True:
        for k,v in dict1.items():
            if a==k:
                return v
    return False
    

Assessment 7 problem 5

## Write a function called checkingIfIn that takes three parameters. The first is a required parameter, which should be a string. The second is an optional parameter called direction with a default value of True. The third is an optional parameter called d that has a default value of {'apple': 2, 'pear': 1, 'fruit': 19, 'orange': 5, 'banana': 3, 'grapes': 2, 'watermelon': 7}. Write the function checkingIfIn so that when the second parameter is True, it checks to see if the first parameter is a key in the third parameter; if it is, return True, otherwise return False.

But if the second paramter is False, then the function should check to see if the first parameter is not a key of the third. If it’s not, the function should return True in this case, and if it is, it should return False.




def checkingIfIn(a,direction=True,d={'apple': 2, 'pear': 1, 'fruit': 19, 'orange': 5, 'banana': 3, 'grapes': 2, 'watermelon': 7}):
    if direction == True:
        if a in d:
                return True
        else:
                return False
    
    else:
        if a not in d:
            return True
        else:
            return False

Assessment 7 problem 6

## We have provided the function checkingIfIn such that if the first input parameter is in the third, dictionary, input parameter, then the function returns that value, and otherwise, it returns False. Follow the instructions in the active code window for specific variable assignmemts.


def checkingIfIn(a, direction = True, d = {'apple': 2, 'pear': 1, 'fruit': 19, 'orange': 5, 'banana': 3, 'grapes': 2, 'watermelon': 7}):
    if direction == True:
        if a in d:
            return d[a]
        else:
            return False
    else:
        if a not in d:
            return True
        else:
            return d[a]

# Call the function so that it returns False and assign that function call to the variable c_false
c_false=checkingIfIn("mula")
# Call the fucntion so that it returns True and assign it to the variable c_true
c_true=checkingIfIn("coffee",direction = False)

# Call the function so that the value of fruit is assigned to the variable fruit_ans
fruit_ans=checkingIfIn("fruit",direction = True)


# Call the function using the first and third parameter so that the value 8 is assigned to the variable param_check
param_check= checkingIfIn("jaam", direction = True, d = {'jaam':8})
    

Assignment Problem 1

## Write a function, sublist, that takes in a list of numbers as the parameter. In the function, use a while loop to return a sublist of the input list. The sublist should contain the same values of the original list up until it reaches the number 5 (it should not contain the number 5).

def sublist(list):
    new_list=[]
    i=0
    while i < len(list):
        if list[i] == 5:
            break
        new_list.append(list[i])
        i=i+1
    return new_list

integer_list=[1,2,3,4,5]
list=integer_list

sublist(list)

Assignment Problem 2

## Write a function called check_nums that takes a list as its parameter, and contains a while loop that only stops once the element of the list is the number 7. What is returned is a list of all of the numbers up until it reaches 7.

def check_nums(list):
    i=0
    New_list=[]
    while i < len(list):
        if list[i] == 7:
            break
        New_list.append(list[i])
        i=i+1
    return New_list
    
integer_list=[1,2,3,4,5,6,7,8,9]
list=integer_list
print (check_nums(list))

Assignment Problem 3

## Write a function, sublist, that takes in a list of strings as the parameter. In the function, use a while loop to return a sublist of the input list. The sublist should contain the same values of the original list up until it reaches the string “STOP” (it should not contain the string “STOP”).

def sublist(list):
    i=0
    New_list=[]
    
    while i < len(list):
        if list[i] == "STOP":
            break
        New_list.append(list[i])
        i=i+1
    return New_list
New_string_list=["aam","jaam","kola","pepe","kathal"]

list=New_string_list

print (sublist(list))

Assignment Problem 4

##Write a function called stop_at_z that iterates through a list of strings. Using a while loop, append each string to a new list until the string that appears is “z”. The function should return the new list.

def stop_at_z(list):
    i=0
    New_list=[]
    
    while i < len(list):
        if list[i] == "z":
            break
        New_list.append(list[i])
        i=i+1
    return New_list
New_string_list=["a","j","k","p","k"]

list=New_string_list

print (stop_at_z(list))

Assignment Problem 5

## Below is a for loop that works. Underneath the for loop, rewrite the problem so that it does the same thing, but using a while loop instead of a for loop. Assign the accumulated total in the while loop code to the variable sum2. Once complete, sum2 should equal sum1.

sum1 = 0

lst = [65, 78, 21, 33]

for x in lst:
    sum1 = sum1 + x

i=0
sum2=0
while i <len(lst):
    sum2=sum2+lst[i]
    i=i+1
    

Assignment Problem 6

## Challenge: Write a function called beginning that takes a list as input and contains a while loop that only stops once the element of the list is the string ‘bye’. What is returned is a list that contains up to the first 10 strings, regardless of where the loop stops. (i.e., if it stops on the 32nd element, the first 10 are returned. If “bye” is the 5th element, the first 4 are returned.) If you want to make this even more of a challenge, do this without slicing.

def beginning(list):
    i=0
    New_list=[]
    
    while i < len(list):
        if list[i] == "bye":
            break
        New_list.append(list[i])
        i=i+1
    part1=New_list[:10]
    return part1
New_string_list=["alu","jam","kola","potol","kamranga","bye","morich"]

list=New_string_list

print (beginning(list))

Break Keyword

while True:
    print("this phrase will always print")
    break
    print("Does this phrase print?")

print("We are done with the while loop.")

By asking the user for prices and keeping a running total and count of items. When the last item is entered, the program gives the grand total, number of items, and average price.

## We’ll need these variables:

total - this will start at zero
count - the number of items, which also starts at zero
moreItems - a boolean that tells us whether more items are waiting; this starts as True

def checkout():
    total = 0
    count = 0
    moreItems = True
    while moreItems:
        price = float(input('Enter price of item (0 when done): '))
        if price != 0:
            count = count + 1
            total = total + price
            print('Subtotal: $', total)
        else:
            moreItems = False
    average = total / count
    print('Total items:', count)
    print('Total $', total)
    print('Average price per item: $', average)

checkout()

Continue Keyword

x = 0
while x < 10:
    print("we are incrementing x")
    if x % 2 == 0:
        x += 3
        continue
    if x % 3 == 0:
        x += 5
    x += 1
print("Done with our loop! X has the value: " + str(x))

Currently the function is supposed to take 1 required parameter, and 2 optional parameters, however the code doesn’t work. Fix the code so that it passes the test. This should only require changing one line of code.

## Currently the function is supposed to take 1 required parameter, and 2 optional parameters, however the code doesn’t work. Fix the code so that it passes the test. This should only require changing one line of code.

def waste(mar,var = "Water",marble = "type"):
    final_string = var + " " + marble + " " + mar
    return final_string

Define a function called multiply. It should have one required parameter, a string. It should also have one optional parameter, an integer, named mult_int, with a default value of 10. The function should return the string multiplied by the integer. (i.e.: Given inputs “Hello”, mult_int=3, the function should return “HelloHelloHello”)

Define a function called multiply. It should have one required parameter, a string. It should also have one optional parameter, an integer, named mult_int, with a default value of 10. The function should return the string multiplied by the integer. (i.e.: Given inputs “Hello”, mult_int=3, the function should return “HelloHelloHello”)


def multiply(x,mult_int=10):
        return x*mult_int

Format pattern

# this works
names = ["Jack","Jill","Mary"]
for n in names:
    print("'{}!' she yelled. '{}! {}, {}!'".format(n,n,n,"say hello"))

# but this also works!
names = ["Jack","Jill","Mary"]
for n in names:
    print("'{0}!' she yelled. '{0}! {0}, {1}!'".format(n,"say hello"))

Keyword Parameters with Format

names_scores = [("Jack",[67,89,91]),("Emily",[72,95,42]),("Taylor",[83,92,86])]
for name, scores in names_scores:
    print("The scores {nm} got were: {s1},{s2},{s3}.".format(nm=name,s1=scores[0],s2=scores[1],s3=scores[2]))

listener loop

## One very common pattern is called a listener loop. Inside the while loop there is a function call to get user input. The loop repeats indefinitely, until a particular input is received.

theSum = 0
x = -1
while (x != 0):
    x = int(input("next number to add up (enter 0 if no more numbers): "))
    theSum = theSum + x

print(theSum)

Optional Parameter Example-1

initial = 7
def f(x, y =3, z=initial):
	   print("x, y, z, are: " + str(x) + ", " + str(y) + ", " + str(z))
	
f(2)
f(2, 5)
f(2, 5, 8)

Output:
x, y, z, are: 2, 3, 7
x, y, z, are: 2, 5, 7
x, y, z, are: 2, 5, 8

Optional Parameter Example-2

def f(a, L=[]):
    L.append(a)
    return L
	
print(f(1))
print(f(2))
print(f(3))
print(f(4, ["Hello"]))
print(f(5, ["Hello"]))

Output:

[1]
[1, 2]
[1, 2, 3]
['Hello', 4]
['Hello', 5]

Optional Parameter Exercise 1

Write a function called str_mult that takes in a required string parameter and an optional integer parameter. The default value for the integer parameter should be 3. The function should return the string multiplied by the integer parameter.

def str_mult(a,b=3):
    return a*b

Turtle Movement with Coin Flip

import random
import turtle

def isInScreen(w,t):
    leftBound = - w.window_width() / 2
    rightBound = w.window_width() / 2
    topBound = w.window_height() / 2
    bottomBound = -w.window_height() / 2

    turtleX = t.xcor()
    turtleY = t.ycor()

    stillIn = True
    if turtleX > rightBound or turtleX < leftBound:
        stillIn = False
    if turtleY > topBound or turtleY < bottomBound:
        stillIn = False

    return stillIn

t = turtle.Turtle()
wn = turtle.Screen()

t.shape('turtle')
while isInScreen(wn,t):
    coin = random.randrange(0, 2)
    if coin == 0:
        t.left(90)
    else:
        t.right(90)

    t.forward(50)

wn.exitonclick()

Validating Input

## Let’s say you want a function that asks a yes-or-no question. In this case, you want to make sure that the person using your program enters either a Y for yes or N for no (in either upper or lower case). Here is a program that uses a while loop to keep asking until it receives a valid answer. 

def get_yes_or_no(message):
    valid_input = False
    while not valid_input:
        answer = input(message)
        answer = answer.upper() # convert to upper case
        if answer == 'Y' or answer == 'N':
            valid_input = True
        else:
            print('Please enter Y for yes or N for no.')
    return answer

response = get_yes_or_no('Do you like lima beans? Y)es or N)o: ')
if response == 'Y':
    print('Great! They are very healthy.')
else:
    print('Too bad. If cooked right, they are quite tasty.')

While Loop Problem-1

## Write a while loop that is initialized at 0 and stops at 15. If the counter is an even number, append the counter to a list called eve_nums.

eve_nums=[]
count=0

while count<=15:
    if count%2==0:
        eve_nums.append(count)
    count=count+1

While Loop Problem-2

Below, we’ve provided a for loop that sums all the elements of list1. Write code that accomplishes the same task, but instead uses a while loop. Assign the accumulator variable to the name accum.


list1 = [8, 3, 4, 5, 6, 7, 9]

accum=0
idx=0

while idx < len(list1):
    accum = accum + list1[idx]
    idx=idx+1
    

While Loop Problem-3

## Write a function called stop_at_four that iterates through a list of numbers. Using a while loop, append each number to a new list until the number 4 appears. The function should return the new list.


def stop_at_four(list):
    New_list=[]
    i=0
    while i < len(list):
        if list[i]==4:   
            break
        New_list.append(list[i])
        i=i+1
    return New_list

list=[1,2,3,4]
stop_at_four(list)

While Statement

def sumTo(aBound):
    """ Return the sum of 1+2+3 ... n """

    theSum  = 0
    aNumber = 1
    while aNumber <= aBound:
        theSum = theSum + aNumber
        aNumber = aNumber + 1
    return theSum

print(sumTo(4))

print(sumTo(1000))

Assessment 7 problem 5

"""
Write a function called checkingIfIn that takes three parameters.
The first is a required parameter, which should be a string.
The second is an optional parameter called direction with a default value of True.
The third is an optional parameter called d that has a default value of {'apple': 2, 'pear': 1, 'fruit': 19, 'orange': 5, 'banana': 3, 'grapes': 2, 'watermelon': 7}.

Write the function checkingIfIn so that when the second parameter is True, it checks to see if the first parameter is a key in the third parameter; if it is, return True, otherwise return False.

But if the second paramter is False, then the function should check to see if the first parameter is not a key of the third. If it’s not, the function should return True in this case, and if it is, it should return False.
"""

def checkingIfIn(a, direction = True, d = {'apple': 2, 'pear': 1, 'fruit': 19, 'orange': 5, 'banana': 3, 'grapes': 2, 'watermelon': 7}):
    if direction:
        return bool(d.get(a, False)) and bool(d[a])
    elif not direction:
        return not bool(d.get(a, False))