1 files changed, 5 insertions, 0 deletions
diff --git a/tests/pyb/timer_callback.py b/tests/pyb/timer_callback.py
index 864dd479e..51242fba4 100644
--- a/tests/pyb/timer_callback.py
+++ b/tests/pyb/timer_callback.py
@@ -8,19 +8,24 @@ def cb1(t):
     print("cb1")
     t.callback(None)
 
+
 # callback function that disables the timer when called
 def cb2(t):
     print("cb2")
     t.deinit()
 
+
 # callback where cb4 closes over cb3.y
 def cb3(x):
     y = x
+
     def cb4(t):
         print("cb4", y)
         t.callback(None)
+
     return cb4
 
+
 # create a timer with a callback, using callback(None) to stop
 tim = Timer(1, freq=100, callback=cb1)
 pyb.delay(5)