已经去掉开头的（六个字符）"data: "
第一句：
{"id":"33500ba6-958c-43df-bc89-89101d1e413e","object":"chat.completion.chunk","created":1739722122,"model":"deepseek-reasoner","system_fingerprint":"fp_5417b77867","choices":[{"index":0,"delta":{"role":"assistant","content":null,"reasoning_content":""},"logprobs":null,"finish_reason":null}]}
content与reasoning_content都为null，并且有一个-> "role":"assistant"中间句：
先返回推理（reasoning_content），再返回内容（content）；即先content为null，reasoning_content有数据，再content有数据，reasoning_content为null 。
倒数第二句：
{"id":"33500ba6-958c-43df-bc89-89101d1e413e","object":"chat.completion.chunk","created":1739722122,"model":"deepseek-reasoner","system_fingerprint":"fp_5417b77867","choices":[{"index":0,"delta":{"content":"","reasoning_content":null},"logprobs":null,"finish_reason":"stop"}],"usage":{"prompt_tokens":6,"completion_tokens":217,"total_tokens":223,"prompt_tokens_details":{"cached_tokens":0},"completion_tokens_details":{"reasoning_tokens":188},"prompt_cache_hit_tokens":0,"prompt_cache_miss_tokens":6}}结尾句：
[DONE]