lint with black python. convert f style strings to old one. some small fixes

vrtManager/rwlock.py

@@ -11,11 +11,9 @@ found at: http://code.activestate.com/recipes/502283-read-write-lock-class-rlock
 
 # Imports
 # -------
-
 from threading import Condition, Lock, currentThread
 from time import time
 
-
 # Read write lock
 # ---------------
 
@@ -138,9 +136,7 @@ class ReadWriteLock(object):
                     # else also wants to upgrade, there is no way we can do
                     # this except if one of us releases all his read locks.
                     # Signal this to user.
-                    raise ValueError(
-                        "Inevitable dead lock, denying write lock"
-                    )
+                    raise ValueError("Inevitable dead lock, denying write lock")
                 upgradewriter = True
                 self.__upgradewritercount = self.__readers.pop(me)
             else: