demo都跑不起来，各种报错，无奈弃了 ，唉

[wkingnet]

(QA) E:\code\quantdigger>python demo.py
[I 210123 00:24:34 dsutil:17] register datasource: <class 'quantdigger.datasource.impl.csv_source.CsvSource'> => csv
[I 210123 00:24:34 dsutil:17] register datasource: <class 'quantdigger.datasource.impl.tushare_source.TuShareSource'> => tushare
[I 210123 00:24:34 dsutil:17] register datasource: <function CachedTuShareSource at 0x000001A5AB59A840> => cached-tushare
[I 210123 00:24:34 dsutil:17] register datasource: <class 'quantdigger.datasource.impl.mongodb_source.MongoDBSource'> => mongodb
[I 210123 00:24:34 dsutil:17] register datasource: <class 'quantdigger.datasource.impl.sqlite_source.SqliteSource'> => sqlite
Traceback (most recent call last):
File "demo.py", line 1, in
from quantdigger import *
File "E:\code\quantdigger\quantdigger_init_.py", line 3, in
from quantdigger.engine.strategy import *
File "E:\code\quantdigger\quantdigger\engine\strategy.py", line 2, in
from quantdigger.engine.execute_unit import ExecuteUnit
File "E:\code\quantdigger\quantdigger\engine\execute_unit.py", line 9, in
from quantdigger.engine.context import Context
File "E:\code\quantdigger\quantdigger\engine\context_init_.py", line 1, in
from .data_context import OriginalData
File "E:\code\quantdigger\quantdigger\engine\context\data_context.py", line 25
self.default_pcontract: str = None
^
SyntaxError: invalid syntax

(QA) E:\code\quantdigger>