diff --git a/rhodecode/lib/pidlock.py b/rhodecode/lib/pidlock.py
--- a/rhodecode/lib/pidlock.py
+++ b/rhodecode/lib/pidlock.py
@@ -24,7 +24,6 @@ import errno
 from multiprocessing.util import Finalize
 
 
-
 class LockHeld(Exception):
     pass
 
@@ -49,7 +48,7 @@ class DaemonLock(object):
         self.desc = desc
         self.debug = debug
         self.held = False
-        #run the lock automatically !
+        # run the lock automatically !
         self.lock()
         self._finalize = Finalize(self, DaemonLock._on_finalize,
                                   args=(self, debug), exitpriority=10)
@@ -58,7 +57,7 @@ class DaemonLock(object):
     def _on_finalize(lock, debug):
         if lock.held:
             if debug:
-                print('leck held finilazing and running lock.release()')
+                print('lock held finalazing and running lock.release()')
             lock.release()
 
     def lock(self):
@@ -66,7 +65,7 @@ class DaemonLock(object):
         locking function, if lock is present it
         will raise LockHeld exception
         """
-        lockname = '%s' % (os.getpid())
+        lockname = f'{os.getpid()}'
         if self.debug:
             print('running lock')
         self.trylock()
@@ -85,8 +84,8 @@ class DaemonLock(object):
                     running_pid = -1
 
             if self.debug:
-                print('lock file present running_pid: %s, '
-                      'checking for execution' % (running_pid,))
+                print(f'lock file present running_pid: {running_pid}, '
+                      f'checking for execution')
             # Now we check the PID from lock file matches to the current
             # process PID
             if running_pid:
@@ -94,15 +93,14 @@ class DaemonLock(object):
                     os.kill(running_pid, 0)
                 except OSError as exc:
                     if exc.errno in (errno.ESRCH, errno.EPERM):
-                        print("Lock File is there but"
-                              " the program is not running")
-                        print("Removing lock file for the: %s" % running_pid)
+                        print("Lock File is there but the program is not running")
+                        print(f"Removing lock file for the: {running_pid}")
                         self.release()
                     else:
                         raise
                 else:
                     print("You already have an instance of the program running")
-                    print("It is running as process %s" % running_pid)
+                    print(f"It is running as process {running_pid}")
                     raise LockHeld()
 
         except IOError as e:
@@ -118,16 +116,16 @@ class DaemonLock(object):
         if self.callbackfn:
             # execute callback function on release
             if self.debug:
-                print('executing callback function %s' % self.callbackfn)
+                print(f'executing callback function {self.callbackfn}')
             self.callbackfn()
         try:
             if self.debug:
-                print('removing pidfile %s' % self.pidfile)
+                print(f'removing pidfile {self.pidfile}')
             os.remove(self.pidfile)
             self.held = False
         except OSError as e:
             if self.debug:
-                print('removing pidfile failed %s' % e)
+                print(f'removing pidfile failed {e}')
             pass
 
     def makelock(self, lockname, pidfile):
@@ -138,7 +136,7 @@ class DaemonLock(object):
         :param pidfile: the file to write the pid in
         """
         if self.debug:
-            print('creating a file %s and pid: %s' % (pidfile, lockname))
+            print(f'creating a file {lockname} and pid: {pidfile}')
 
         dir_, file_ = os.path.split(pidfile)
         if not os.path.isdir(dir_):