labs/Module-2/4.Methods-Functions/03-Function Practice Exercises.ipynb

Function Practice Exercises

Problems are arranged in increasing difficulty:

• Warmup - these can be solved using basic comparisons and methods
• Level 1 - these may involve if/then conditional statements and simple methods
• Level 2 - these may require iterating over sequences, usually with some kind of loop
• Challenging - these will take some creativity to solve

WARMUP SECTION:

LESSER OF TWO EVENS: Write a function that returns the lesser of two given numbers if both numbers are even, but returns the greater if one or both numbers are odd

lesser_of_two_evens(2,4) --> 2
lesser_of_two_evens(2,5) --> 5

In [ ]:

def lesser_of_two_evens(a,b):
    pass

In [ ]:

# Check
lesser_of_two_evens(2,4)

In [ ]:

# Check
lesser_of_two_evens(2,5)

ANIMAL CRACKERS: Write a function takes a two-word string and returns True if both words begin with same letter

animal_crackers('Levelheaded Llama') --> True
animal_crackers('Crazy Kangaroo') --> False

In [ ]:

def animal_crackers(text):
    pass

In [ ]:

# Check
animal_crackers('Levelheaded Llama')

In [ ]:

# Check
animal_crackers('Crazy Kangaroo')

MAKES TWENTY: Given two integers, return True if the sum of the integers is 20 or if one of the integers is 20. If not, return False

makes_twenty(20,10) --> True
makes_twenty(12,8) --> True
makes_twenty(2,3) --> False

In [ ]:

def makes_twenty(n1,n2):
    pass

In [ ]:

# Check
makes_twenty(20,10)

In [ ]:

# Check
makes_twenty(2,3)

LEVEL 1 PROBLEMS

OLD MACDONALD: Write a function that capitalizes the first and fourth letters of a name

old_macdonald('macdonald') --> MacDonald

Note: 'macdonald'.capitalize() returns 'Macdonald'

In [ ]:

def old_macdonald(name):
    pass

In [ ]:

# Check
old_macdonald('macdonald')

MASTER YODA: Given a sentence, return a sentence with the words reversed

master_yoda('I am home') --> 'home am I'
master_yoda('We are ready') --> 'ready are We'

Note: The .join() method may be useful here. The .join() method allows you to join together strings in a list with some connector string. For example, some uses of the .join() method:

>>> "--".join(['a','b','c'])
>>> 'a--b--c'

This means if you had a list of words you wanted to turn back into a sentence, you could just join them with a single space string:

>>> " ".join(['Hello','world'])
>>> "Hello world"

In [ ]:

def master_yoda(text):
    pass

In [ ]:

# Check
master_yoda('I am home')

In [ ]:

# Check
master_yoda('We are ready')

ALMOST THERE: Given an integer n, return True if n is within 10 of either 100 or 200

almost_there(90) --> True
almost_there(104) --> True
almost_there(150) --> False
almost_there(209) --> True

NOTE: abs(num) returns the absolute value of a number

In [ ]:

def almost_there(n):
    pass

In [ ]:

# Check
almost_there(104)

In [ ]:

# Check
almost_there(150)

In [ ]:

# Check
almost_there(209)

LEVEL 2 PROBLEMS

FIND 33:

Given a list of ints, return True if the array contains a 3 next to a 3 somewhere.

has_33([1, 3, 3]) → True
has_33([1, 3, 1, 3]) → False
has_33([3, 1, 3]) → False

In [ ]:

def has_33(nums):
    pass

In [ ]:

# Check
has_33([1, 3, 3])

In [ ]:

# Check
has_33([1, 3, 1, 3])

In [ ]:

# Check
has_33([3, 1, 3])

PAPER DOLL: Given a string, return a string where for every character in the original there are three characters

paper_doll('Hello') --> 'HHHeeellllllooo'
paper_doll('Mississippi') --> 'MMMiiissssssiiippppppiii'

In [ ]:

def paper_doll(text):
    pass

In [ ]:

# Check
paper_doll('Hello')

In [ ]:

# Check
paper_doll('Mississippi')

BLACKJACK: Given three integers between 1 and 11, if their sum is less than or equal to 21, return their sum. If their sum exceeds 21 and there's an eleven, reduce the total sum by 10. Finally, if the sum (even after adjustment) exceeds 21, return 'BUST'

blackjack(5,6,7) --> 18
blackjack(9,9,9) --> 'BUST'
blackjack(9,9,11) --> 19

In [ ]:

def blackjack(a,b,c):
    pass

In [ ]:

# Check
blackjack(5,6,7)

In [ ]:

# Check
blackjack(9,9,9)

In [ ]:

# Check
blackjack(9,9,11)

SUMMER OF '69: Return the sum of the numbers in the array, except ignore sections of numbers starting with a 6 and extending to the next 9 (every 6 will be followed by at least one 9). Return 0 for no numbers.

summer_69([1, 3, 5]) --> 9
summer_69([4, 5, 6, 7, 8, 9]) --> 9
summer_69([2, 1, 6, 9, 11]) --> 14

In [ ]:

def summer_69(arr):
    pass

In [ ]:

# Check
summer_69([1, 3, 5])

In [ ]:

# Check
summer_69([4, 5, 6, 7, 8, 9])

In [ ]:

# Check
summer_69([2, 1, 6, 9, 11])

CHALLENGING PROBLEMS

SPY GAME: Write a function that takes in a list of integers and returns True if it contains 007 in order

 spy_game([1,2,4,0,0,7,5]) --> True
 spy_game([1,0,2,4,0,5,7]) --> True
 spy_game([1,7,2,0,4,5,0]) --> False

In [ ]:

def spy_game(nums):
    pass

In [ ]:

# Check
spy_game([1,2,4,0,0,7,5])

In [ ]:

# Check
spy_game([1,0,2,4,0,5,7])

In [ ]:

# Check
spy_game([1,7,2,0,4,5,0])

COUNT PRIMES: Write a function that returns the number of prime numbers that exist up to and including a given number

count_primes(100) --> 25

By convention, 0 and 1 are not prime.

In [ ]:

def count_primes(num):
    pass
                

In [ ]:

# Check
count_primes(100)

Just for fun:

PRINT BIG: Write a function that takes in a single letter, and returns a 5x5 representation of that letter

print_big('a')

out:   *  
      * *
     *****
     *   *
     *   *

HINT: Consider making a dictionary of possible patterns, and mapping the alphabet to specific 5-line combinations of patterns.
For purposes of this exercise, it's ok if your dictionary stops at "E".

In [ ]:

def print_big(letter):
    pass

In [ ]:

print_big('a')