RaspberryPi #5 Matrix Switch and RFID Show OLED

import RPi.GPIO as GPIO
import time
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
col=[26,19,13,6]
row=[21,20,16,7]
for x in row:
    GPIO.setup(x, GPIO.IN, pull_up_down=GPIO.PUD_UP)
for y in col:
    GPIO.setup(y,GPIO.OUT)
    GPIO.output(y,0)
keypad=[
                    [1,2,3,"A"],
                    [4,5,6,"B"],
                    [7,8,9,"C"],
                    ["E",0,"F","D"]
                    ]
k=''
cc=0
a=0
def button_pressed(channel):
    global keypad,cc,k
    a=1
    while a:
        for x in range(4):
            GPIO.output(col[x],0)
            for y in range (4):
                if GPIO.input(row[y])==0:
                    while  GPIO.input(row[y])==0:
                        pass
                    k+=str(keypad[y][x])
                    cc+=1
                    a=0
                    print (k,end='\r')
            GPIO.output(col[x],1)
GPIO.add_event_detect(21, GPIO.RISING, callback=button_pressed,
bouncetime=300)
GPIO.add_event_detect(20, GPIO.RISING, callback=button_pressed,
bouncetime=300)
GPIO.add_event_detect(16, GPIO.RISING, callback=button_pressed,
bouncetime=300)
GPIO.add_event_detect(7, GPIO.RISING, callback=button_pressed,
bouncetime=300)
import time
import Adafruit_SSD1306

from PIL import Image,ImageDraw,ImageFont

# Raspberry Pi pin configuration:
RST = 1

# 128x64 display with hardware I2C:
disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST)

# Note you can change the I2C address by passing an i2c_address parameter like:
# disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST, i2c_address=0x3C)

# Initialize library.
disp.begin()
# Clear display.
disp.clear()
import datetime
import binascii
import sys
import Adafruit_PN532 as PN532
# Configuration for a Raspberry Pi:
CS   = 8
MOSI = 10
MISO = 9
SCLK = 11

# Create an instance of the PN532 class.
pn532 = PN532.PN532(cs=CS, sclk=SCLK, mosi=MOSI, miso=MISO)

# Call begin to initialize communication with the PN532.  Must be done before
# any other calls to the PN532!
pn532.begin()

# Get the firmware version from the chip and print(it out.)
ic, ver, rev, support = pn532.get_firmware_version()
print('Found PN532 with firmware version: {0}.{1}'.format(ver, rev))

# Configure PN532 to communicate with MiFare cards.
pn532.SAM_configuration()

# Main loop to detect cards and read a block.
print('Waiting for MiFare card...')
while 1:
    now = datetime.datetime.now()
    now2 =now.strftime("%H:%M")
    now1=now.strftime("%d/%m/%Y")
    if cc==8:
        if k=="01234567":
            width = disp.width
            height = disp.height
            image = Image.new('1', (width, height))
            draw = ImageDraw.Draw(image)
            font = ImageFont.truetype('VCR_OSD_MONO_1.001.ttf',22)
            draw.text((0,0), 'Antman',font=font, fill=1)
            disp.image(image)
            disp.display()
            k=''
            cc=0
            with open("December.txt", "a") as text_file:
                text_file.write("Code:012345678  Name:Antman  Date: %s Time: %s\n" % (now1,now2))
        elif k=="89ABCDEF":
            width = disp.width
            height = disp.height
            image = Image.new('1', (width, height))
            draw = ImageDraw.Draw(image)
            font = ImageFont.truetype('VCR_OSD_MONO_1.001.ttf',22)
            draw.text((0,0), 'Ironman',font=font, fill=1)
            disp.image(image)
            disp.display()
            k=''
            cc=0
            with open("December.txt", "a") as text_file:
                text_file.write("Code:89ABCDEF  Name:Ironman  Date: %s Time: %s\n" % (now1,now2))
        else:
            width = disp.width
            height = disp.height
            image = Image.new('1', (width, height))
            draw = ImageDraw.Draw(image)
            font = ImageFont.truetype('VCR_OSD_MONO_1.001.ttf',18)
            draw.text((0,0), 'Access Denied',font=font, fill=1)
            disp.image(image)
            disp.display()
            k=''
            cc=0
    uid = pn532.read_passive_target()
    # Try again if no card is available.
    if uid is None:
        continue
    uid_str = str(binascii.hexlify(uid),'ascii')
    if uid_str=="6a93305b":
            width = disp.width
            height = disp.height
            image = Image.new('1', (width, height))
            draw = ImageDraw.Draw(image)
            font = ImageFont.truetype('VCR_OSD_MONO_1.001.ttf',22)
            draw.text((0,0), 'Spiderman',font=font, fill=1)
            print ('Found card with UID:0x{}'.format(uid_str))
            disp.image(image)
            disp.display()
            k=''
            cc=0
            with open("December.txt", "a") as text_file:
                text_file.write("Code:0x6a93305b  Name:Spiderman  Date: %s Time: %s\n" % (now1,now2))
    elif uid_str=="0665d093":
            width = disp.width
            height = disp.height
            image = Image.new('1', (width, height))
            draw = ImageDraw.Draw(image)
            font = ImageFont.truetype('VCR_OSD_MONO_1.001.ttf',22)
            draw.text((0,0), 'Superman',font=font, fill=1)
            print ('Found card with UID:0x{}'.format(uid_str))
            disp.image(image)
            disp.display()
            k=''
            cc=0
            with open("December.txt", "a") as text_file:
                text_file.write("Code:0x0665d093  Name:Superman  Date: %s Time: %s\n" % (now1,now2))
    else:
        width = disp.width
        height = disp.height
        image = Image.new('1', (width, height))
        draw = ImageDraw.Draw(image)
        font = ImageFont.truetype('VCR_OSD_MONO_1.001.ttf',18)
        draw.text((0,0), 'Access denied',font=font, fill=1)
        print ('Found card with UID:0x{}'.format(uid_str))
        disp.image(image)
        disp.display()
        k=''
        cc=0