db_utils/interactions/features_interactions.py: replace distance (null) with 0...

db_utils/interactions/features_interactions.py: replace distance (null) with 0 for exons that have different IDs, but identical coordinates

src/db_utils/interactions/features_interactions.py

@@ -282,8 +282,8 @@ def add_info_distance_between_features(df: pd.DataFrame) -> pd.DataFrame:
     studied in interaction and to add this information in the result dataframe.
     If the result is NULL it is because we study two exons or genes located in
     the same chromosome.
-    If the result is (null), so NaN, it is because we study two exons or genes
-    which have different identifiers, but strictly identical coordinates.
+    If the result is 0, it is because we study two exons or genes which have
+    different identifiers, but strictly identical coordinates.
 
     :param df: Result of the "filtering_2" function
     :return df: df with distances added or NULL or (null) see before for more
@@ -310,6 +310,8 @@ def add_info_distance_between_features(df: pd.DataFrame) -> pd.DataFrame:
             (df["start1"] - df["stop2"] + 1)
         df.loc[df["stop1"] > df["stop2"], "distance"] = \
             (df["start1"] - df["stop2"] + 1)
+        df.loc[(df["start1"] == df["start2"]) & (df["stop1"] == df["stop2"]),
+               "distance"] = 0
         df.loc[df["chr1"] != df["chr2"], "distance"] = "NULL"
         df.drop(["start1", "ID1", "chr1", "stop1", "ID2", "chr2", "start2",
                  "stop2"], axis='columns', inplace=True)
@@ -331,6 +333,8 @@ def add_info_distance_between_features(df: pd.DataFrame) -> pd.DataFrame:
             (df["start1"] - df["stop2"] + 1)
         df.loc[df["stop1"] > df["stop2"], "distance"] = \
             (df["start1"] - df["stop2"] + 1)
+        df.loc[(df["start1"] == df["start2"]) & (df["stop1"] == df["stop2"]),
+               "distance"] = 0
         df.loc[df["chr1"] != df["chr2"], "distance"] = "NULL"
         df.drop(["start1", "ID1", "chr1", "stop1", "ID2", "chr2",
                  "start2", "stop2"], axis='columns', inplace=True)