unsigned long datapack(void *inBuf, unsigned long len, void *outBuf) { WORD16 *hdr; BYTE *in = (BYTE *)inBuf; BYTE *out = (BYTE *)outBuf; BYTE *pscrc; BYTE *ptr = out; unsigned long i; unsigned long fcs = ~(crc32_le(~0, in, len)); *ptr++ = 0x55; *ptr++ = 0xAA; hdr = (WORD16 *)ptr; ptr += 2; *ptr++ = 0x7e; *ptr++ = 0x7e; for (i = 0; i < len; i++) { switch (in[i]) { case 0x7d: *ptr++ = 0x7d; *ptr++ = 0x5d; break; case 0x7e: *ptr++ = 0x7d; *ptr++ = 0x5e; break; default: *ptr++ = in[i]; break; } } pscrc = (BYTE *)&fcs; for (i = 0; i < 4; i++, pscrc++) { switch (*pscrc) { case 0x7d: *ptr++ = 0x7d; *ptr++ = 0x5d; break; case 0x7e: *ptr++ = 0x7d; *ptr++ = 0x5e; break; default: *ptr++ = *pscrc; break; } } *ptr++ = 0x7e; *ptr++ = 0x7e; *hdr = ptr - out - 4; return ptr - out; } 转化为python程序

Here's the Python equivalent of the given C function:

import struct
import binascii

def datapack(inBuf, length, outBuf):
    inBytes = struct.unpack(str(length)+'B', inBuf)
    fcs = binascii.crc32(bytes(inBytes)) ^ 0xffffffff
    outBytes = bytearray()
    outBytes.append(0x55)
    outBytes.append(0xAA)
    outBytes.extend(struct.pack('<H', length))
    outBytes.append(0x7e)
    outBytes.append(0x7e)
    for b in inBytes:
        if b == 0x7d:
            outBytes.extend([0x7d, 0x5d])
        elif b == 0x7e:
            outBytes.extend([0x7d, 0x5e])
        else:
            outBytes.append(b)
    for i in range(4):
        pscrc = (fcs >> (i * 8)) & 0xff
        if pscrc == 0x7d:
            outBytes.extend([0x7d, 0x5d])
        elif pscrc == 0x7e:
            outBytes.extend([0x7d, 0x5e])
        else:
            outBytes.append(pscrc)
    outBytes.append(0x7e)
    outBytes.append(0x7e)
    struct.pack_into('<H', outBytes, 2, len(outBytes) - 6)
    outBuf[:len(outBytes)] = outBytes
    return len(outBytes)

Note: This implementation assumes that `inBuf`, `len`, and `outBuf` are already byte arrays in Python. If they are not, you may need to modify the code accordingly.