python-functions-solutions.ipynb

Kernel: Python 2

Practice Python Functions

_Author: Ryan Dunlap (San Francisco)

Resources: Potentially Helpful Functions

• Dictionary Comprehension

• Enumerate

• Length

• Int

• List

Nowadays, most of the string module's components are already built into Python. However, it still has several constant values that can be useful, including:

string.ascii_uppercase

import string

string.ascii_uppercase

'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

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1) Write a function that takes the length of a side of a square as an argument and returns the area of the square.

def area_square(length):
    
    area = length ** 2
    
    return area

We can use the assert statement to validate if our function's output is correct.

assert area_square(5) == 25

# If our assert statement is false, assert will return an error.

assert area_square(5) == 21

---------------------------------------------------------------------------
AssertionError                            Traceback (most recent call last)
<ipython-input-4-e5f18b8a7bbc> in <module>()
      1 # If our assert statement is false, assert will return an error.
      2 
----> 3 assert area_square(5) == 21

AssertionError: 

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2) Write a function that takes the height and width of a triangle and returns the area.

def area_triangle(height,width):
    
    area = width * height * (1/2.0)
    
    return area

assert area_triangle(2,2) == 2
assert area_triangle(5,5) == 12.5

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3) Write a function that takes a string as an argument and returns a tuple consisting of two elements:

• A list of all of the characters in the string.

• A count of the number of characters in the string.

def string_list_fun(user_string):

    string_list = list(user_string)
    string_count = len(string_list)
    
    return (string_list,string_count)

assert string_list_fun('Ryan Rocks') == (['R','y','a','n',' ','R','o','c','k','s'],10)
string_list_fun('Ryan Rocks')

(['R', 'y', 'a', 'n', ' ', 'R', 'o', 'c', 'k', 's'], 10)

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4) Write a function that takes two integers, passed as strings, and returns the sum, difference, and product as a tuple (with all values as integers).

def math_rocks(number_1, number_2):
    
    int_1 = int(number_1)
    int_2 = int(number_2)
    
    my_sum = int_1 + int_2
    my_diff = int_1 - int_2
    my_prod = int_1 * int_2
    
    return (my_sum, my_diff, my_prod)

assert math_rocks ('5','2') == (7,3,10)
math_rocks('5','2')

(7, 3, 10)

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5) Write a function that takes a list as the argument and returns a tuple consisting of two elements:

• A list with the items in reverse order.

• A list of the items in the original list that have an odd index.

def getting_crazy(my_list):
    # We can use -1 to reverse index the list:
    reverse_list = my_list[::-1]
    
    # Start from index 1 and grab every other index from there (1,3,5 etc.):
    odd_list = my_list[1::2]
    
    return (reverse_list,odd_list)

assert getting_crazy([1,2,3,4,5]) == ([5,4,3,2,1],[2,4])
getting_crazy([1,2,3,4,5])

([5, 4, 3, 2, 1], [2, 4])

---

Challenge: Write a function that returns the score for a word. A word's score is the sum of the scores of its letters. Each letter's score is equal to its position in the alphabet.

So, for example:

• A = 1, B = 2, C = 3, D = 4, E = 5

• abe = 8 = (1 + 2 + 5)

Hint: The string library has a property ascii_lowercase that can save some typing here.

def score_word(user_word):
    # Creates a dictionary of letters and associated scores:
    letter_score = {letter:counter + 1 for counter,letter in enumerate(string.ascii_lowercase)}
    # Added level to ensure letters used are uniform:
    lower_word = user_word.lower()
    
    # Baseline score to add to:
    score = 0
    
    # Iterates through the argument word and adds their scores to the total:
    for letter in lower_word:
        score += letter_score[letter]
        
    return score

assert score_word("abe") == 8