PyScript中asyncio事件顺序不符，如何等待getWords执行完成？

问题原因 #

你当前的代码用asyncio.ensure_future(getWords())只是把异步协程提交到事件循环，但不会等待它执行完毕，所以后续的print("4. ...")会直接运行；同时getWords内部的my_Words是局部变量，外部无法获取到异步请求的结果。

修改方案 #

1. 让getWords函数返回异步请求得到的结果
2. 使用await关键字等待getWords执行完成，确保顺序执行并接收返回值

修改后的完整代码 #

from request import request
import asyncio
import json

async def getWords():
    print("2. INSIDE GETWORDS:")
    baseurl = "http://localhost:4000/wordscape"

    body = json.dumps({"sqlline": sqlline})
    headers = {"Content-type": "application/json"}
    response = await request(f"{baseurl}/read", body=body, method="POST", headers=headers)

    my_Words = await response.string()
    print("3. MYWORDS inside getWords:", my_Words)
    return my_Words  # 返回异步请求结果

sqlline = "select upper(word) as word from dictionary.dictionary_words_20230103 where word = 'help'\n"
print("1. BUILD SQL:", sqlline)
my_Words = await getWords()  # 等待协程执行完成并获取结果
print("4. ####WORDS RETURNED FROM getWords:", my_Words)

替代方案（若顶层await不兼容） #

如果你的环境不支持顶层await，可以把逻辑封装到主协程中，用asyncio.run触发执行：

from request import request
import asyncio
import json

async def getWords():
    print("2. INSIDE GETWORDS:")
    baseurl = "http://localhost:4000/wordscape"

    body = json.dumps({"sqlline": sqlline})
    headers = {"Content-type": "application/json"}
    response = await request(f"{baseurl}/read", body=body, method="POST", headers=headers)

    my_Words = await response.string()
    print("3. MYWORDS inside getWords:", my_Words)
    return my_Words

async def main():
    sqlline = "select upper(word) as word from dictionary.dictionary_words_20230103 where word = 'help'\n"
    print("1. BUILD SQL:", sqlline)
    my_Words = await getWords()
    print("4. ####WORDS RETURNED FROM getWords:", my_Words)

asyncio.run(main())

修改后输出顺序 #

1. BUILD SQL: select upper(word) as word from dictionary.dictionary_words_20230103 where word = 'help'

2. INSIDE GETWORDS:
3. MYWORDS inside getWords: [
  {
    "word": "HELP"
  }
]
4. ####WORDS RETURNED FROM getWords: [
  {
    "word": "HELP"
  }
]

内容的提问来源于stack exchange，提问作者99Valk