Python KeyError, qr code barcode reader on raspberry pi

I'm a Korean. English translation may be wrong. I am making a program that can output data in Python using a qr reader that is received as a usb input from a Raspberry Pi 4. The code below raises KeyError:74 . What's the workaround?

ss += hid[int(ord(c))]

Below is the full code.

import sys

hid = {4: 'a', 5: 'b', 6: 'c', 7: 'd', 8: 'e', 9: 'f', 10: 'g', 11: 'h', 12: 'i', 13: 'j', 14: 'k', 15: 'l', 16: 'm',

       17: 'n', 18: 'o', 19: 'p', 20: 'q', 21: 'r', 22: 's', 23: 't', 24: 'u', 25: 'v', 26: 'w', 27: 'x', 28: 'y',

       29: 'z', 30: '1', 31: '2', 32: '3', 33: '4', 34: '5', 35: '6', 36: '7', 37: '8', 38: '9', 39: '0', 44: ' ',

       45: '-', 46: '=', 47: '[', 48: ']', 49: '\\', 51: ';', 52: '\'', 53: '~', 54: ',', 55: '.', 56: '/'}

hid2 = {4: 'A', 5: 'B', 6: 'C', 7: 'D', 8: 'E', 9: 'F', 10: 'G', 11: 'H', 12: 'I', 13: 'J', 14: 'K', 15: 'L', 16: 'M',

    17: 'N', 18: 'O', 19: 'P', 20: 'Q', 21: 'R', 22: 'S', 23: 'T', 24: 'U', 25: 'V', 26: 'W', 27: 'X', 28: 'Y',

    29: 'Z', 30: '!', 31: '@', 32: '#', 33: '$', 34: '%', 35: '^', 36: '&', 37: '*', 38: '(', 39: ')', 44: ' ',

    45: '_', 46: '+', 47: '{', 48: '}', 49: '|', 51: ':', 52: '"', 53: '~', 54: '<', 55: '>', 56: '?'}

fp = open('/dev/hidraw4', 'rb')

ss = ""

shift = False

done = False

while not done:

## Get the character from the HID

buffer = fp.read(8)

for c in buffer:

    if ord(c) > 0:

        ##  40 is carriage return which signifies

        ##  we are done looking for characters

        if int(ord(c)) == 40:

            done = True

            break;

        ##  If we are shifted then we have to 

        ##  use the hid2 characters.

        if shift: 

            ## If it is a '2' then it is the shift key

            if int(ord(c)) == 2 :

                shift = True

            ## if not a 2 then lookup the mapping

            else:

                ss += hid2[int(ord(c))]

                shift = False

        ##  If we are not shifted then use

        ##  the hid characters

        else:

            ## If it is a '2' then it is the shift key

            if int(ord(c)) == 2 :

                shift = True

            ## if not a 2 then lookup the mapping

            else:

                ss += hid[int(ord(c))]

print(ss)