Document extract_stressful_events.

features/esm_SAM.py

@@ -25,6 +25,25 @@ GROUP_QUESTIONNAIRES_BY = [
 
 
 def extract_stressful_events(df_esm: pd.DataFrame) -> pd.DataFrame:
+    """
+    Extract information about stressful events.
+
+    Participants were asked: "Was there a particular event that created tension in you?"
+    Then a subset of questions related to this event followed.
+    This function goes through the follow-up questions one by one
+        and preprocesses them, so that it adds new columns to the dataframe.
+
+    Parameters
+    ----------
+    df_esm: pd.DataFrame
+        A raw dataframe of all ESM data.
+
+    Returns
+    -------
+    df_esm_events: pd.DataFrame
+        A cleaned up df of Stress Appraisal Measure items with additional columns.
+
+    """
     # 0. Select only questions from Stress Appraisal Measure.
     df_esm_preprocessed = features.esm.preprocess_esm(df_esm)
     df_esm_sam = df_esm_preprocessed[