Add data analysis feature for report (#918)

* Add data analysis feature for report

* better display

qlib/contrib/report/data/base.py

@@ -0,0 +1,36 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+"""
+This module is responsible for analysing data
+
+Assumptions
+- The analyse each feature individually
+
+"""
+import pandas as pd
+from blocks.utils.log import logt
+from qlib.contrib.report.utils import sub_fig_generator
+
+
+class FeaAnalyser:
+    def __init__(self, dataset: pd.DataFrame):
+        self._dataset = dataset
+        with logt("calc_stat_values"):
+            self.calc_stat_values()
+
+    def calc_stat_values(self):
+        pass
+
+    def plot_single(self, col, ax):
+        raise NotImplementedError(f"This type of input is not supported")
+
+    def skip(self, col):
+        return False
+
+    def plot_all(self, *args, **kwargs):
+
+        ax_gen = iter(sub_fig_generator(*args, **kwargs))
+        for col in self._dataset:
+            if not self.skip(col):
+                ax = next(ax_gen)
+                self.plot_single(col, ax)