Backup.py -> backup.py, also some PEP conformity-changes

Which also includes two TODO-Tasks.
We had not proven ourselfs worthy of the holy-PEP-construct yet, so we
have to rename the whole file to backu.py, which follows snake_case, and
it's classes members.
They now embrace it as they should've done in the first place!

The dragon which we just encountered isnt as big as we thought and we
can still fight it with our as-easy-as-it-gets task to just snip out the
class and give it it's own residence under lib/backup.py-File!

private/backup.py

@@ -1,4 +1,9 @@
 #!/usr/bin/env python3
+""" This module is thought to be the main point to export and import users.
+It's actually not really a module but a script ought to be run from the command line
+
+@TODO: Wording of module header...
+"""
 
 import configparser
 import csv
@@ -10,9 +15,10 @@ import lib.uis.default as default_cmd  # Follows -u, -a, -f flags
 
 class Backup:
     """Backups a Tilde database to an CSV file
+    @TODO: Move class into own file
 
     :Example:
-    >>> from Backup import Backup
+    >>> from backup import Backup
     >>> from ListUsers import ListUsers
     >>> L = ListUsers.ListUsers("/path/to/sqlite").get_fetch()
     >>> backup_db = Backup("stdout")
@@ -37,12 +43,13 @@ class Backup:
         :type dialect: str
         """
 
-        self.setFilename(output)
-        self.setQuoting(quoting)
-        self.setDialect(dialect)
-        self.setFieldnames(tuple(['id', 'username', 'email', 'name', 'pubkey', 'timestamp', 'status']))
+        self.set_filename(output)
+        self.set_quoting(quoting)
+        self.set_dialect(dialect)
+        self.set_field_names(tuple(['id', 'username', 'email', 'name',
+                                    'pubkey', 'timestamp', 'status']))
 
-    def setDialect(self, dialect: str) -> None:
+    def set_dialect(self, dialect: str) -> None:
         """ Set dialect for Object
 
         :param dialect: Dialect to set for Object
@@ -53,7 +60,7 @@ class Backup:
 
         self.dialect = dialect
 
-    def setQuoting(self, quoting: int) -> None:
+    def set_quoting(self, quoting: int) -> None:
         """ Set quoting in the CSV(must be supported by the CSV Module!)
 
         :param quoting: Quoting Integer given by csv.QUOTE_* constants
@@ -64,7 +71,7 @@ class Backup:
 
         self.quoting = quoting
 
-    def setFilename(self, filename: str) -> None:
+    def set_filename(self, filename: str) -> None:
         """ Sets Filename to output to
 
         :param filename: Filename to output to(set stdout for stdout)
@@ -75,8 +82,8 @@ class Backup:
 
         self.filename = filename
 
-    def setFieldnames(self, f_names: tuple) -> None:
-        """ Set fieldname to process
+    def set_field_names(self, f_names: tuple) -> None:
+        """ Set field name to process
 
         :param f_names: Fieldnames-Tuple
         :type f_names: tuple
@@ -95,20 +102,22 @@ class Backup:
         """
 
         returner = io.StringIO()
-        write_csv = csv.DictWriter(returner, fieldnames=self.field_names, quoting=self.quoting, dialect=self.dialect)
+        write_csv = csv.DictWriter(returner, fieldnames=self.field_names,
+                                   quoting=self.quoting, dialect=self.dialect)
         write_csv.writeheader()
         for row in fetched:
             write_csv.writerow(dict(row))
-            # sqlite3.Row doesn't "easily" convert to a dict itself sadly, so just a quick help from us here
-            # it actually even delivers a list(sqlite3.Row) also, which doesnt make the life a whole lot easier
+            # sqlite3.Row doesn't "easily" convert to a dict itself sadly,
+            # so just a quick help from us here
+            # it actually even delivers a list(sqlite3.Row) also,
+            # which doesnt make the life a whole lot easier
 
         if self.filename == "stdout":
             print(returner.getvalue())
-            return True
         else:
             with open(self.filename, "w") as f:
                 print(returner.getvalue(), file=f)
-            return True
+        return True
 
 
 if __name__ == "__main__":
@@ -121,7 +130,7 @@ if __name__ == "__main__":
     fetch = L.get_fetch()
     if fetch:
         B = Backup(args.file)
-        B.setFieldnames(fetch[0].keys())  # sqlite3.row delivers its keys for us! SO NICE!
+        B.set_field_names(fetch[0].keys())  # sqlite3.row delivers its keys for us! SO NICE!
         B.backup_to_file(fetch)
     else:
         print("nothing to backup!")