The right way to Resolve: Lend a hand the Bookseller Problem in Python

A bookseller has plenty of books categorised in 26 classes categorized A, B, … Z. Each and every e book has a code c of three, 4, 5 or extra characters. The first personality of a code is a capital letter which defines the e book class.

Within the bookseller’s stocklist every code c is adopted through an area and through a favorable integer n (int n >= 0) which signifies the volume of books of this code in inventory.

For instance an extract of a stocklist may well be:

L = {"ABART 20", "CDXEF 50", "BKWRK 25", "BTSQZ 89", "DRTYM 60"}.
or
L = ["ABART 20", "CDXEF 50", "BKWRK 25", "BTSQZ 89", "DRTYM 60"] or ....
You are going to be given a stocklist (e.g. : L) and a listing of classes in capital letters e.g :

M = {"A", "B", "C", "W"}
or
M = ["A", "B", "C", "W"] or ...
and your activity is to seek out the entire books of L with codes belonging to every class of M and to sum their amount in line with every class.

For the lists L and M of instance you need to go back the string:

(A : 20) - (B : 114) - (C : 50) - (W : 0)
the place A, B, C, W are the types, 20 is the sum of the original e book of class A, 114 the sum similar to “BKWRK” and “BTSQZ”, 50 similar to “CDXEF” and nil to class ‘W’ since there aren’t any code starting with W.

If L or M are empty go back string is “”.

Notes:

• Within the consequence codes and their values are in the similar order as in M.
• See “Samples Exams” for the go back.

The Resolution in Python

Possibility 1

def stock_list(listOfArt, listOfCat):
    if (len(listOfArt) == 0) or (len(listOfCat) == 0):
        go back ""
    consequence = ""
    for cat in listOfCat:
        overall = 0
        for e book in listOfArt:
            if (e book[0] == cat[0]):
                overall += int(e book.break up(" ")[1])
        if (len(consequence) != 0):
            consequence += " - "
        consequence += "(" + str(cat) + " : " + str(overall) + ")"
    go back consequence

Possibility 2

from collections import Counter

def stock_list(listOfArt, listOfCat):
    if now not listOfArt:
        go back ''
    codePos = listOfArt[0].index(' ') + 1
    cnt = Counter()
    for s in listOfArt:
        cnt[s[0]] += int(s[codePos:])
    go back ' - '.sign up for('({} : {})'.layout(cat, cnt[cat]) for cat in listOfCat)

Possibility 3

def stock_list(stocklist, classes):
    if now not stocklist or now not classes:
        go back ""
    go back " - ".sign up for(
        "({} : {})".layout(
            class,
            sum(int(merchandise.break up()[1]) for merchandise in stocklist if merchandise[0] == class))
        for class in classes)

Check instances to validate the answer

from answer import stock_list
import take a look at

@take a look at.describe("Trying out")
def _():
    @take a look at.it("Exams")
    def _():
        b = ["BBAR 150", "CDXE 515", "BKWR 250", "BTSQ 890", "DRTY 600"]
        c = ["A", "B", "C", "D"]
        take a look at.assert_equals(stock_list(b, c), "(A : 0) - (B : 1290) - (C : 515) - (D : 600)")

        b = ["ABAR 200", "CDXE 500", "BKWR 250", "BTSQ 890", "DRTY 600"]
        c = ["A", "B"]
        take a look at.assert_equals(stock_list(b, c), "(A : 200) - (B : 1140)")

        b = ["CBART 20", "CDXEF 50", "BKWRK 25", "BTSQZ 89", "DRTYM 60"]
        c = ["A", "B", "C", "W"]
        take a look at.assert_equals(stock_list(b, c), "(A : 0) - (B : 114) - (C : 70) - (W : 0)")

        b = ["ROXANNE 102", "RHODODE 123", "BKWRKAA 125", "BTSQZFG 239", "DRTYMKH 060"]
        c = ["B", "R", "D", "X"]
        take a look at.assert_equals(stock_list(b, c), "(B : 364) - (R : 225) - (D : 60) - (X : 0)")

        b = []
        c = ["B", "R", "D", "X"]
        take a look at.assert_equals(stock_list(b, c), "")

        b = ["ROXANNE 102", "RHODODE 123", "BKWRKAA 125", "BTSQZFG 239", "DRTYMKH 060"]
        c = []
        take a look at.assert_equals(stock_list(b, c), "")

        b = ["ROXANNE 102", "RHODODE 123", "BKWRKAA 125", "BTSQZFG 239", "DRTYMKH 060"]
        c = ["U", "V", "R"]
        take a look at.assert_equals(stock_list(b, c), "(U : 0) - (V : 0) - (R : 225)")