python - python和C之间的二进制I/O

Question

我正在尝试使用 Python 将用 C 编写的二进制文件与 HDF5 文件进行转换。要读取二进制文件，Python 的工作方式如下：

pos=np.fromfile(f, count=npt*3, dtype='f4').reshape((npt, 3))

要编写我尝试过的相同的东西，但没有成功，array.tofile() 现在我正在尝试使用这样的 ctypes（将网上找到的不同答案拼接在一起）：

import ctypes as c

print "Loading C libraries with ctype"
libc = c.CDLL("libc.so.6") # Linux

# fopen()
libc.fopen.restype = c.c_void_p
def errcheck(res, func, args):
    if not res: raise IOError
    return res

libc.fopen.errcheck = errcheck
# errcheck() could be similarly defined for `fwrite`, `fclose` 

c_int_p = c.POINTER(c.c_int)
c_float_p = c.POINTER(c.c_float)
c_double_p = c.POINTER(c.c_double)


def c_write(data, f, numpy_type, c_type_p, nbyte, count):
    data = data.astype(numpy_type)
    data_p = data.ctypes.data_as(c_type_p)
    nitems  = libc.fwrite(data_p, nbyte, count, f)
    if nitems != data.size: # not all data were written
        print "Not all data were written, exit..."
        sys.exit()


c_write(pos, f, np.int32, c_int_p, 4, npart.size)

Answer 1

您可能应该查看该struct模块，它非常适合在最低字节/字节级别打包和解包数据。