Python_functions.ipynb

Kernel: Python 3

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'

---

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

# A:
def square(x):
    return x**2

square(4)

16

---

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

# A:

def area_triangle(b,h):
    return 1/2*b*h

area_triangle(3,4)

6.0

---

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.

# A:

def string_manipulation(string):
    length_string = len(string)
    string_chars = list(set(string))
    return (string_chars, length_string)

_, char_count = string_manipulation('this is a sentence')

char_count

18

---

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).

# A:

def int_string(x, y):
    x = int(x)
    y = int(y)
    return (x+y, x-y, x*y)

int_string('1','2')

(3, -1, 2)

---

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.

for number, value in enumerate(['a','b','c']):
    print(number, value)

0 a
1 b
2 c

# A:

def list_manipulation(l):
    l_reversed = l[::-1]
    
    odd_index = []
    for number, i in enumerate(l):
        if number %2 ==1:
            odd_index.append(i)
    
    ## alt: l[1::2] 
        
    return l_reversed, odd_index

    # return l[::-1], l[1::2] one liner


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

([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.

string.ascii_lowercase

'abcdefghijklmnopqrstuvwxyz'

list(zip(string.ascii_lowercase, range(1,27)))

[('a', 1),
 ('b', 2),
 ('c', 3),
 ('d', 4),
 ('e', 5),
 ('f', 6),
 ('g', 7),
 ('h', 8),
 ('i', 9),
 ('j', 10),
 ('k', 11),
 ('l', 12),
 ('m', 13),
 ('n', 14),
 ('o', 15),
 ('p', 16),
 ('q', 17),
 ('r', 18),
 ('s', 19),
 ('t', 20),
 ('u', 21),
 ('v', 22),
 ('w', 23),
 ('x', 24),
 ('y', 25),
 ('z', 26)]

# A:

def word_score(input_string):
    string_lower = input_string.lower()
    
    values_dict = dict(zip(string.ascii_lowercase, range(1,27)))
    
    score = 0 
    for letter in string_lower:
        score += values_dict[letter]
    
    return score

word_score('data')

26

values_dict = dict(zip(string.ascii_lowercase, range(1,26)))
values_dict

{'a': 1,
 'b': 2,
 'c': 3,
 'd': 4,
 'e': 5,
 'f': 6,
 'g': 7,
 'h': 8,
 'i': 9,
 'j': 10,
 'k': 11,
 'l': 12,
 'm': 13,
 'n': 14,
 'o': 15,
 'p': 16,
 'q': 17,
 'r': 18,
 's': 19,
 't': 20,
 'u': 21,
 'v': 22,
 'w': 23,
 'x': 24,
 'y': 25}

my_string = 'this is a string'
list(set(my_string))

['g', 't', ' ', 'a', 's', 'r', 'n', 'h', 'i']