Add with_std, with_counts to create_table_one (#748)

* Issue 747: Add with_std, with_counts to create_table_one

causalml/match.py

@@ -31,7 +31,7 @@ def smd(feature, treatment):
     return (t.mean() - c.mean()) / np.sqrt(0.5 * (t.var() + c.var()))
 
 
-def create_table_one(data, treatment_col, features):
+def create_table_one(data, treatment_col, features, with_std=True, with_counts=True):
     """Report balance in input features between the treatment and control groups.
 
     References:
@@ -42,6 +42,8 @@ def create_table_one(data, treatment_col, features):
         data (pandas.DataFrame): total or matched sample data
         treatment_col (str): the column name for the treatment
         features (list of str): the column names of features
+        with_std (bool): whether to output std together with mean values as in <mean> (<std>) format
+        with_counts (bool): whether to include a row counting the total number of samples
 
     Returns:
         (pandas.DataFrame): A table with the means and standard deviations in
@@ -51,19 +53,27 @@ def create_table_one(data, treatment_col, features):
     t1 = pd.pivot_table(
         data[features + [treatment_col]],
         columns=treatment_col,
-        aggfunc=[lambda x: "{:.2f} ({:.2f})".format(x.mean(), x.std())],
+        aggfunc=[
+            lambda x: (
+                "{:.2f} ({:.2f})".format(x.mean(), x.std())
+                if with_std
+                else "{:.2f}".format(x.mean())
+            )
+        ],
     )
     t1.columns = t1.columns.droplevel(level=0)
     t1["SMD"] = data[features].apply(lambda x: smd(x, data[treatment_col])).round(4)
 
-    n_row = pd.pivot_table(
-        data[[features[0], treatment_col]], columns=treatment_col, aggfunc=["count"]
-    )
-    n_row.columns = n_row.columns.droplevel(level=0)
-    n_row["SMD"] = ""
-    n_row.index = ["n"]
+    if with_counts:
+        n_row = pd.pivot_table(
+            data[[features[0], treatment_col]], columns=treatment_col, aggfunc=["count"]
+        )
+        n_row.columns = n_row.columns.droplevel(level=0)
+        n_row["SMD"] = ""
+        n_row.index = ["n"]
+
+        t1 = pd.concat([n_row, t1], axis=0)
 
-    t1 = pd.concat([n_row, t1], axis=0)
     t1.columns.name = ""
     t1.columns = ["Control", "Treatment", "SMD"]
     t1.index.name = "Variable"