Warm-up 2

Last two characters

Write suffix(code) that returns the last two characters of a string that has at least two characters.

suffix("BRD-001")  ->  "01"

def suffix(code):
    ...

Long name?

Write is_long(name) that returns True if the name has more than ten characters.

is_long("sourdough bread")  ->  True
is_long("milk")             ->  False

def is_long(name):
    ...

Price with tax

Write with_tax(price) that returns the price plus 10% tax, rounded to two decimal places.

with_tax(40)     ->  44.0
with_tax(2.5)    ->  2.75
with_tax(19.99)  ->  21.99

def with_tax(price):
    ...

A line of dashes

Write rule(n) that returns a string of n dashes, for underlining a receipt. rule(0) is the empty string.

rule(5)  ->  "-----"

def rule(n):
    ...

Items in order

prices maps item names to prices. Write item_names(prices) that returns the item names as a list in alphabetical order.

item_names({"milk": 2.5, "apple": 40, "bread": 25})  ->  ["apple", "bread", "milk"]

def item_names(prices):
    ...

Second cheapest

Write second_cheapest(prices) that returns the second smallest number in a list of at least two different numbers.

second_cheapest([40, 2.5, 25])  ->  25

def second_cheapest(prices):
    ...

Everything but the first

Write rest(items) that returns a new list with everything except the first item. For an empty list return an empty list.

rest(["apple", "bread", "milk"])  ->  ["bread", "milk"]
rest([])                          ->  []

def rest(items):
    ...

Same items, any order

Two lists hold item names, possibly with repeats and in any order. Write same_items(a, b) that returns True if they contain the same set of distinct items.

same_items(["apple", "milk", "apple"], ["milk", "apple"])  ->  True
same_items(["apple"], ["apple", "milk"])                   ->  False

def same_items(a, b):
    ...

Front of the line

Write next_customer(line) that returns the name at the front of a deque, without removing it. The line is never empty.

next_customer(deque(["Ada", "Grace"]))  ->  "Ada"

from collections import deque

def next_customer(line):
    ...

Describe stock

Write describe(item, quantity) that returns the text <item>: <quantity> left.

describe("bread", 3)  ->  "bread: 3 left"

def describe(item, quantity):
    ...

Next: Warm-up 3.