Something when wrong during the obfuscation. Wrong shellcode format?

[AbdulRafeyKhan]

def gen_shellcode(self, shellcode):
    shellcode = shellcode.replace("\r", "").replace("\n", "")
    try:
        key = self.gen_key()
        self.ui.print_msg("Generating obfuscation key 0x%s".join([f'\\x{b:02x}' for b in data]))
        #self.ui.print_msg("Generating obfuscation key 0x%s" % key.encode().hex())
        shellcode = self.pad_shellcode(shellcode)
        magic = self.gen_magic()
        self.ui.print_msg("Generating magic bytes %s" % hex(magic))
        shellcode = hex(magic)[2:10].decode("hex") + shellcode
        shellcode = self.xor_payload(shellcode, key)
        size = len(shellcode)
        shellcode = self.set_decoder(hex(magic)[2:10].decode("hex"), (size - 4)) + shellcode
        for i in range(1, 5):
            shellcode = shellcode.replace("[RAND" + str(i) + "]", self.gen_pop(hex(self.gen_magic())[2:10].decode("hex")))
        self.ui.print_msg("Final shellcode length is %s (%d) bytes" % (hex(len(shellcode)), len(shellcode)))
        if self.is_debug():
            print
        return shellcode
    except:
        self.ui.print_error("Something when wrong during the obfuscation. Wrong shellcode format?")
        return False

can you explain me this piece of code it's showing error again and again

[AbdulRafeyKhan]

please help me out i am not able to understand where the error is in this code