python 分片上传大格式

form-data类型

    def multipart_producer(boundary, filename):
        """构建 multipart, 返回 yield, 实现分片上传"""
        import time,chardet,os,mimetypes
        def _encode(_str):
            if not _str.strip():
                return _str
            if isinstance(_str, unicode):
                return _str.encode('utf-8')
            encoding = chardet.detect(_str).get('encoding') or 'utf-8'
            # print _str, encoding
            return _str.decode(encoding).encode('utf-8', 'ignore')

        boundary_bytes = boundary.encode()
        filename_bytes = _encode(filename)
        start = time.time()
        file_size = os.path.getsize(filename)
        file_size_mb = round(float(file_size) / 1024 / 1024, 2)
        mtype = mimetypes.guess_type(filename)[0] or "application/octet-stream"
        buf = (
            (b"--%s
" % boundary_bytes)
            + (
                b'Content-Disposition: form-data; name="file"; filename="%s"
'
                % (filename_bytes,)
            )
            + (b"Content-Type: %s
" % mtype.encode())
            + b"
"
        )
        # print buf
        yield buf
        with open(filename, "rb") as f:
            while True:
                # 16k at a time.
                chunk = f.read(160 * 1024)
                # 打印上传进度
                if time.time() - start > 5:
                    start = time.time()
                    print 'Total size: {} MB, Process {} %'.format(
                        file_size_mb,
                        round(float(f.tell()) / file_size * 100, 2)
                    )
                if not chunk:
                    break
                yield chunk
        yield b"
"
        yield b"--%s--
" % (boundary_bytes,)

　　使用方法

boundary = uuid4().hex
        file_name = os.path.basename(path)
        print '开始上传 {}'.format(file_name)
        headers = {
            'Content-Type': 'multipart/form-data; boundary={0}'.format(boundary), 'charset': 'UTF-8'}
        data = multipart_producer(boundary, path)