add format argument to bumblebee.util.bytefmt()

it has a default value to be backwards compatible

bumblebee/util.py

@@ -45,7 +45,7 @@ def execute(cmd, wait=True):
     logging.info(u"command returned '{}'".format("" if not rv else rv))
     return rv
 
-def bytefmt(num):
+def bytefmt(num, fmt="{:.2f}"):
     """
         format a value of bytes to a more human readable pattern
         example: 15 * 1024 becomes 15KiB
@@ -54,13 +54,15 @@ def bytefmt(num):
 
             num (int): bytes
 
+            fmt (string): format
+
         Return: string
     """
     for unit in ["", "Ki", "Mi", "Gi"]:
         if num < 1024.0:
-            return "{:.2f}{}B".format(num, unit)
+            return "{}{}B".format(fmt, unit).format(num)
         num /= 1024.0
-    return "{:.2f}GiB".format(num*1024.0)
+    return "{}GiB".format(fmt).format(num*1024.0)
 
 def durationfmt(duration, shorten=False, suffix=False):
     duration = int(duration)