tafunc: 参照 PEP8 修改 import 格式

Author: shinny-mayanqiong

tqsdk/tafunc.py

@@ -10,12 +10,13 @@
 import datetime
 import math
 from typing import Union
+
 import numpy as np
 import pandas as pd
 from scipy import stats
 
-import tqsdk.sim
 import tqsdk.objs
+import tqsdk.sim
 
 
 def ref(series, n):