update README and add summary stats func

README.md

@@ -13,6 +13,7 @@ Catherine Meng, Jessie Zhang, Zheng He
 -   **`missing_value_summary`**\
     This function is to provide a summary of missing values in the dataset.
 -   **`get_summary_statistics`**
+    Generate summary statistics for specified columns or all columns if none are provided.
 
 ## Installation
 

src/pyeda/data_summary.py

@@ -0,0 +1,21 @@
+def get_summary_statistics(df, col = None):
+    """
+    Generate summary statistics for specified columns or all columns if none are provided.
+
+    This function will return the important statistics (e.g. mean, min, std) for numeric columns, as well as
+    some key metrics (e.g. count, unique) for non-numeric columns.
+    
+    Parameters
+    ----------
+    df : pd.DataFrame
+        The dataframe containing the data for analysis.
+    col : list or None
+        A list of column names for which to get statistics. 
+        Default value is None, the function will apply for all columns.
+
+    Returns
+    ----------
+    pd.DataFrame
+        A DataFrame with summary statistics for the specified columns.
+    """
+    pass