Question

每当我尝试运行此代码

def BinToHex(x):
    a = hex(int(x,2))
    return a[2:]

def HexToBin(x):
    b = bin(int(x,16))[2:]
    return b

c = 0
with open("input.txt") as l:
    for line in l:
        c += 1
    l.close()

x = ""

def main():
    Write = open("binary.txt","w")
    Read = open("input.txt", "r")
    for i in range(c):
        bakwaas = Read.readline()
        d = bakwaas.split()
        opcode = d[0]
        address = d[1]
        li = {"cla":"7800","cma":"7400","inc":"7200","hlt":"7100","inp":"f800","out":"f400","ski":"f200","sko":"f100","ion":"f080","iof":"f040"}
        la = {"and":"000","lda":"010","add":"001","sta":"011","bun":"100","call":"101","sub":"110"}
        if opcode in li:
            u = li[opcode]
            hexaNum1 = HexToBin(u)
            if len(hexaNum1) == 16:
                hexaNum1 = hexaNum1
            else:
                hexaNum1 = "0" + hexaNum1
            Write.write(hexaNum1)
            x += hexaNum1
            Write.write("\n")
        else:
            hexaNum2 = address[:3]
            arr = opcode[:3]
            ad = la[arr]
            if opcode[-1]=="#":
                ad = "0" + ad
            elif opcode[-1]=="@":
                ad = "1" + ad
            temp = ad
            bintemp = HexToBin(hexaNum2)
            hextemp = BinToHex(ad)
            ad = hextemp + bintemp
            temp = "000" + temp + bintemp
            Write.write(temp)
            x  += temp 
            Write.write("\n")


    Write.close()
    Read.close()
    String = x
    BitInString = [String[i:i + 8] for i in range(0, len(String), 8)]
    BytesInString = [int(i,2) for i in BitInString]
    with open("output.bin", "wb") as l:
        l.write(bytearray(BytesInString))
    l.close()
main()

回溯（最近一次通话最后一次）：文件“ exercise.py”，第63行，在 main（）在main中的第51行，文件“ exercise.py” x + = temp UnboundLocalError：赋值之前引用了本地变量'x'

我被分配了一个重新创建汇编器的任务，该汇编器可以用我们选择的更高语言来阅读机器语言。因此，我正在从文本中读取代码内容并进行读取以及写入二进制文件。

我的文本文件包含和@ 123

对于输出，我应该根据我的输入在二进制文件中得到一个2字节大小和0001000100100011的文件。我无法理解此错误试图告诉我什么。

Answer 1

x += hexaNum1转换为x = x + hexaNum1（与x += temp相同），因此需要在操作之前定义x，否则它将不知道要添加哪个值。

您可以通过在x = 0循环之前添加for来轻松解决此问题（前提是您希望x的起始值为默认的整数0）

为什么我收到“ UnboundLocalError：分配前引用了局部变量'x'”

1 个答案: