diff --git a/czsc/__init__.py b/czsc/__init__.py
index f0a587fb7..6f7491b7e 100644
--- a/czsc/__init__.py
+++ b/czsc/__init__.py
@@ -74,6 +74,7 @@
     print_df_sample,
     index_composition,
 
+    AliyunOSS,
     DataClient,
     set_url_token,
     get_url_token,
diff --git a/czsc/utils/__init__.py b/czsc/utils/__init__.py
index d310a5260..32a682607 100644
--- a/czsc/utils/__init__.py
+++ b/czsc/utils/__init__.py
@@ -23,6 +23,7 @@
 from .cache import home_path, get_dir_size, empty_cache_path
 from .index_composition import index_composition
 from .data_client import DataClient, set_url_token, get_url_token
+from .oss import AliyunOSS
 
 
 sorted_freqs = ['Tick', '1分钟', '2分钟', '3分钟', '4分钟', '5分钟', '6分钟', '10分钟', '12分钟',
diff --git a/docs/requirements.txt b/docs/requirements.txt
index cf9fb45ae..eea0f073e 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -27,4 +27,5 @@ plotly>=5.11.0
 parse>=1.19.0
 lightgbm>=4.0.0
 streamlit
-redis
\ No newline at end of file
+redis
+oss2
\ No newline at end of file
diff --git a/examples/test_offline/debug_weight_backtest.py b/examples/test_offline/debug_weight_backtest.py
new file mode 100644
index 000000000..ed723526b
--- /dev/null
+++ b/examples/test_offline/debug_weight_backtest.py
@@ -0,0 +1,4 @@
+import czsc
+import pandas as pd
+
+dfw = pd.read_csv(r"C:\Users\zengb\Desktop\dfw_debug.csv")
diff --git a/requirements.txt b/requirements.txt
index a0dda89ca..f999f0c79 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,4 +21,5 @@ plotly>=5.11.0
 parse>=1.19.0
 lightgbm>=4.0.0
 streamlit
-redis
\ No newline at end of file
+redis
+oss2
\ No newline at end of file