Warm-up 1

Double the price

Write double_price(price) that returns twice the price.

double_price(40)   ->  80
double_price(2.5)  ->  5.0

def double_price(price):
    ...

Shout it

Write shout(text) that returns the text in capitals with an exclamation mark added at the end.

shout("fresh bread")  ->  "FRESH BREAD!"

def shout(text):
    ...

Is the list empty?

Write is_empty(items) that returns True if the list has no items.

is_empty([])         ->  True
is_empty(["bread"])  ->  False

def is_empty(items):
    ...

Middle item

Write middle(items) that returns the item in the middle of a list with an odd number of items.

middle(["apple", "bread", "milk"])  ->  "bread"
middle([7])                         ->  7

def middle(items):
    ...

Count the vowels

Write vowels(text) that returns how many characters of text are vowels: a, e, i, o or u, lowercase only.

vowels("sourdough")  ->  4
vowels("xyz")        ->  0

def vowels(text):
    ...

Is it priced?

Write is_priced(prices, item) that returns True if item is a key in the dictionary prices.

is_priced({"apple": 40}, "apple")  ->  True
is_priced({"apple": 40}, "milk")   ->  False

def is_priced(prices, item):
    ...

First word

Write first_word(sentence) that returns the first word of a sentence. Words are separated by spaces, the sentence has at least one word, and there may be extra spaces before the first word.

first_word("fresh bread daily")  ->  "fresh"
first_word("   apple pie")       ->  "apple"

def first_word(sentence):
    ...

Total stock

stock maps item names to quantities. Write total_stock(stock) that returns the sum of all the quantities.

total_stock({"apple": 10, "bread": 3})  ->  13
total_stock({})                         ->  0

def total_stock(stock):
    ...

Top of the stack

Write push_and_peek(stack, item) that pushes item onto the stack (a list) and returns whatever is now on top.

push_and_peek(["a", "b"], "c")  ->  "c"

def push_and_peek(stack, item):
    ...

Leftover eggs

Eggs are packed in boxes of box_size. Write leftover(eggs, box_size) that returns how many eggs are left after packing as many full boxes as possible.

leftover(20, 6)  ->  2
leftover(12, 6)  ->  0

def leftover(eggs, box_size):
    ...

Next: Warm-up 2.