FIX: updated dataframe needs to be returned

src/caosadvancedtools/table_importer.py

@@ -156,6 +156,9 @@ def win_path_converter(val):
     checks whether the value looks like a windows path and converts it to posix
     """
 
+    if val == "":
+        return val
+
     if not check_win_path(val):
         raise ValueError(
             "Field should be a Windows path, but is\n'{}'.".format(val))
@@ -367,6 +370,8 @@ class TableImporter(object):
         if len(self.unique_keys) > 0:
             df = self.check_unique(df, filename=filename)
 
+        return df
+
 
 class XLSImporter(TableImporter):
     def read_file(self, filename, **kwargs):
@@ -405,7 +410,7 @@ class XLSImporter(TableImporter):
                        'category': "inconsistency"})
             raise DataInconsistencyError(*e.args)
 
-        self.check_dataframe(df, filename)
+        df = self.check_dataframe(df, filename)
 
         return df
 
@@ -422,7 +427,7 @@ class CSVImporter(TableImporter):
                        'category': "inconsistency"})
             raise DataInconsistencyError(*ve.args)
 
-        self.check_dataframe(df, filename)
+        df = self.check_dataframe(df, filename)
 
         return df
 
@@ -439,6 +444,6 @@ class TSVImporter(TableImporter):
                        'category': "inconsistency"})
             raise DataInconsistencyError(*ve.args)
 
-        self.check_dataframe(df, filename)
+        df = self.check_dataframe(df, filename)
 
         return df