correct linter issues

mailcom/inout.py

@@ -29,7 +29,9 @@ def list_of_files(self):
         ]
         if len(self.email_list) == 0:
             raise ValueError(
-                "The directory {} does not contain .eml or .html files. Please check that the directory is containing the email data files".format(
+                """The directory {} does not contain .eml or .html files.
+                Please check that the directory is containing the email
+                data files""".format(
                     mypath
                 )
             )
@@ -81,7 +83,9 @@ def validate_data(self):
         pass
 
     def data_to_xml(self, text):
-        my_item_func = lambda x: "content"
+        def my_item_func(x):
+            return "content"
+
         xml = dicttoxml(text, custom_root="email", item_func=my_item_func)
         return xml.decode()