Btukfyl

I have been getting a TypeError when running the code below. I don't understand why it won't take the length of listLicencePlates, when its a list? I tried to figure out for about an hour now and can't seem to see the mistake. Maybe someone can point out why this happens and how to fix it?

When I run this code:

for x in range[len(listLicencePlates)]:

I get this error:

TypeError: 'type' object is not subscriptable

Here's my full code:

def match_list(witnessedLicensePlate, listLicencePlates):

    matchPlates = len(listLicencePlates)*[len((witnessedLicensePlate))*[""]]

    for x in range[len(listLicencePlates)]:

        y = 0

        for y in range(len(witnessedLicensePlate)):

            if witnessedLicensePlate[y] != listLicencePlates[x][y] and witnessedLicensePlate[y] != "?":

                    y = len(witnessedLicensePlate)

            else:

                matchPlates[x][y] = listLicencePlates[x][y]

    return matchPlates





print(match_list("VF???55",["VX33322","VF12355","VF77455","DA?????","VF10055"]))

I dont know exactly what you want to achieve but I ran the same code and it works fine. Although I must say, I changed range[ to range( as corrected above.

Fixing the TypeError:

The interpreter is telling you exactly where and why you're getting the issue. Here's your MVCE:

>>> range[1]

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

TypeError: 'type' object is not subscriptable

You can't use square brackets, or subscripts (i.e. ) on the built-in range. Rather, use parenthesis (()):

>>> range(1)

range(0, 1)

So change this line:

for x in range[len(listLicencePlates)] # bad news, range[...]

to be

for x in range(len(listLicencePlates)) # Better, range(...)

and you'll get past the TypeError.

Fixing the core issue:

I am guessing, however, that the output you get from this fix isn't what you want. This is the output:

[['V', 'F', '1', '0', '0', '5', '5'], ['V', 'F', '1', '0', '0', '5', '5'], ['V', 'F', '1', '0', '0', '5', '5'], ['V', 'F', '1', '0', '0', '5', '5'], ['V', 'F', '1', '0', '0', '5', '5']]

Which doesn't look useful.

What I think you probably want is an array of bools, where each bool describes whether or not the plate matched character by character, and the "?" represents a wildcard character.

Let's try a more Pythonic and less C-style approach to the problem with some extraordinarily verbose comments:

def match_list2(witnessed_plate, license_plates):

    matching_plates = 

    # just loop through the items, no need for range/indices                                                                                                                                                

    for possible_match in license_plates:

        # If they match, create 2-elt list with           

        # the plate as first elt and whether or not it matches as second    

        # Worry about do_plates_match later. Just get the high level logic

        # down pat and sound first.                                                                               

        matching_plates.append([possible_match,

                                do_plates_match(possible_match, witnessed_plate)])

    return matching_plates



def do_plates_match(plate1, plate2): # Define if they match (the time to worry is upon us)                                                                                                                                                

    # Loop through characters from plate1 and plate2 simultaneously                                                                                                                                     

    for first_char, second_char in zip(plate1, plate2):

        if first_char == "?" or second_char == "?":

            # If we get a question mark, go to the next character                                                                                                                                           

            continue

        elif first_char != second_char:

            # If they don't match at *some* character,

            # we know they can't match regardless of what's next, so return False                                                                                                            

            return False

    # Only way to get here is we must have matched for all characters, return True.                                                                                                                                                    

    return True

and for those who find the comments distracting and would rather just read the code straight away:

def match_list2(witnessed_plate, license_plates):

    matching_plates =                                                                                                                                               

    for possible_match in license_plates:                                                                            

        matching_plates.append([possible_match, do_plates_match(possible_match, witnessed_plate)])

    return matching_plates



def do_plates_match(plate1, plate2):                                                                                                                                                                                                                                                                                  

    for first_char, second_char in zip(plate1, plate2):

        if first_char == "?" or second_char == "?": continue                                                                                                                                          

        elif first_char != second_char: return False                                                                                                                                                                                                                                                         

    return True

Now calling:

plate = "VF???55"

print("Plate: ", plate)

print(match_list2(plate,["VX33322","VF12355","VF77455","DA?????","VF10055"]))

outputs:

Plate:  VF???55

[['VX33322', False], ['VF12355', True], ['VF77455', True], ['DA?????', False], ['VF10055', True]]

clearly showing which plates match, and which don't.

HTH.