buf1.py

import ctypes as c

buffer = c.create_string_buffer(32)
size = c.sizeof(buffer)
addr = c.addressof(buffer)
print(f"Buffer size is {size}d/{size:x}h bytes")
print(f"Buffer address is {addr:08x}h")

def dump(addr, size):
    output = "Hexadecimal dump:\n"
    for i in range(size):
        byte = c.cast(addr+i, c.POINTER(c.c_uint8)).contents.value
        if i%8==0:
            if i: output += "\n"
            output += f"{(addr+i):14}: "
        output += f"{byte:02x} "
    return output


# Write a couple of 4-byte integers to the buffer
integer = c.cast(addr+0, c.POINTER(c.c_uint32)).contents
integer.value = 0x12345678
integer = c.cast(addr+4, c.POINTER(c.c_uint32)).contents
integer.value = 0xdeadbeef
integer = c.cast(addr+16, c.POINTER(c.c_uint32)).contents
integer.value = 0xcafebabe

# Write a couple of bytes to the buffer
byte = c.cast(addr+8, c.POINTER(c.c_uint8)).contents
byte.value = 0x01
byte = c.cast(addr+9, c.POINTER(c.c_uint8)).contents
byte.value = 0x02
byte = c.cast(addr+size-1, c.POINTER(c.c_uint8)).contents
byte.value = 0xFF

# The dump will show the integers we wrote. Note that Intel
# is a small-endian CPU, so the lowest weight bytes come first.
# So the byte order for an integer is reversed vs. how you write
# that integer in hex.
print(dump(addr, size))

# Get rid of the buffer
del buffer

# Now the dump will show junk
print(dump(addr, size))