chatgpt-on-wechat / bot /openai /open_ai_session.py
oliver2023's picture
Duplicate from linhj07/chatgpt-on-wechat
0dc9888
from bot.session_manager import Session
from common.log import logger
class OpenAISession(Session):
def __init__(self, session_id, system_prompt=None, model= "text-davinci-003"):
super().__init__(session_id, system_prompt)
self.model = model
self.reset()
def __str__(self):
# 构造对话模型的输入
'''
e.g. Q: xxx
A: xxx
Q: xxx
'''
prompt = ""
for item in self.messages:
if item['role'] == 'system':
prompt += item['content'] + "<|endoftext|>\n\n\n"
elif item['role'] == 'user':
prompt += "Q: " + item['content'] + "\n"
elif item['role'] == 'assistant':
prompt += "\n\nA: " + item['content'] + "<|endoftext|>\n"
if len(self.messages) > 0 and self.messages[-1]['role'] == 'user':
prompt += "A: "
return prompt
def discard_exceeding(self, max_tokens, cur_tokens= None):
precise = True
try:
cur_tokens = num_tokens_from_string(str(self), self.model)
except Exception as e:
precise = False
if cur_tokens is None:
raise e
logger.debug("Exception when counting tokens precisely for query: {}".format(e))
while cur_tokens > max_tokens:
if len(self.messages) > 1:
self.messages.pop(0)
elif len(self.messages) == 1 and self.messages[0]["role"] == "assistant":
self.messages.pop(0)
if precise:
cur_tokens = num_tokens_from_string(str(self), self.model)
else:
cur_tokens = len(str(self))
break
elif len(self.messages) == 1 and self.messages[0]["role"] == "user":
logger.warn("user question exceed max_tokens. total_tokens={}".format(cur_tokens))
break
else:
logger.debug("max_tokens={}, total_tokens={}, len(conversation)={}".format(max_tokens, cur_tokens, len(self.messages)))
break
if precise:
cur_tokens = num_tokens_from_string(str(self), self.model)
else:
cur_tokens = len(str(self))
return cur_tokens
# refer to https://github.com/openai/openai-cookbook/blob/main/examples/How_to_count_tokens_with_tiktoken.ipynb
def num_tokens_from_string(string: str, model: str) -> int:
"""Returns the number of tokens in a text string."""
import tiktoken
encoding = tiktoken.encoding_for_model(model)
num_tokens = len(encoding.encode(string,disallowed_special=()))
return num_tokens