A bookseller has plenty of books categorized in 26 classes labeled A, B, … Z. Every ebook has a code c of three, 4, 5 or extra characters. The first character of a code is a capital letter which defines the ebook class.

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

For instance an extract of a stocklist might 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’ll be given a stocklist (e.g. : L) and an inventory of classes in capital letters e.g :

`M = {"A", "B", "C", "W"}`

or

`M = ["A", "B", "C", "W"] or ...`

and your activity is to search out all of the books of L with codes belonging to every class of M and to sum their amount in response to every class.

For the lists L and M of instance you must return the string:

`(A : 20) - (B : 114) - (C : 50) - (W : 0)`

the place A, B, C, W are the classes, 20 is the sum of the distinctive ebook of class A, 114 the sum akin to “BKWRK” and “BTSQZ”, 50 akin to “CDXEF” and 0 to class ‘W’ since there are not any code starting with W.

If `L`

or `M`

are empty return string is “”.

Notes:

- Within the outcome codes and their values are in the identical order as in M.
- See “Samples Assessments” for the return.

## The Answer in Python

### Possibility 1

```
def stock_list(listOfArt, listOfCat):
if (len(listOfArt) == 0) or (len(listOfCat) == 0):
return ""
outcome = ""
for cat in listOfCat:
complete = 0
for ebook in listOfArt:
if (ebook[0] == cat[0]):
complete += int(ebook.break up(" ")[1])
if (len(outcome) != 0):
outcome += " - "
outcome += "(" + str(cat) + " : " + str(complete) + ")"
return outcome
```

### Possibility 2

```
from collections import Counter
def stock_list(listOfArt, listOfCat):
if not listOfArt:
return ''
codePos = listOfArt[0].index(' ') + 1
cnt = Counter()
for s in listOfArt:
cnt[s[0]] += int(s[codePos:])
return ' - '.be part of('({} : {})'.format(cat, cnt[cat]) for cat in listOfCat)
```

### Possibility 3

```
def stock_list(stocklist, classes):
if not stocklist or not classes:
return ""
return " - ".be part of(
"({} : {})".format(
class,
sum(int(merchandise.break up()[1]) for merchandise in stocklist if merchandise[0] == class))
for class in classes)
```

## Take a look at instances to validate the answer

```
from answer import stock_list
import take a look at
@take a look at.describe("Testing")
def _():
@take a look at.it("Assessments")
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)")
```