There are some python 'only' rules stated at the '[Python Gotchas][1]' page.

At the beginning they state that:

> **By default**, the GDAL and OGR Python bindings **do not raise exceptions** when errors occur. **Instead they return an error value such as None and write an error message to sys.stdout.**

So first enable the use of exceptions, by issuing `gdal.UseExceptions()` somewhere in the beginning of your script. And secondly catch if any exceptions and do whatever you want with them (including nothing)


 gdal.UseExceptions() # Enable errors
 ...
 try:
 	band.GetStatisticsts() 
 except RuntimeError: # <- Check first what exception is being thrown
 pass


If you're curious here's a [link][2] from python's wiki where they describe the methods of exception handling.


As far as I can tell, using gdal.UseExceptions() will normalize the behaviour of all the methods in the gdal lib, **by making those methods to use the Python Exceptions**. If you really want to ignore all exceptions put the problematic part of your code inside a try/except block eg.:

 >>>
 try:
 	print "1"
 	print "2"
 	a = 0
 	b = 1
 	c = b/a # <- I just divided by zero.
 except:
 	print "Everything is ok" # <- but Everything is Ok. 
 # If you really want to be silent replace with pass
 >>> 1
 2
 'Nothing to see here'

Just be careful, because that way when an exception happens, your script will silently break from the procedure without any indication of what went wrong. 

Also I want to point a couple of things as well:

 1. If you're opt to go that way, you're responsible if your program does. You're choosing to turn a blind eye at any errors that come in your way.
 2. If you catch ALL the exceptions, you will also catch the '[KeyboardInterrupt][3]' exception as well. No more `ctrl-c` (if you're inside a try/except block).
 3. Your code at some point is encountering a processing error. Since you're not using gdal.UseExceptions() you're experiencing that error as a sys.stdout response. Use a try/except block at that point to plug that hole. 



 [1]: http://trac.osgeo.org/gdal/wiki/PythonGotchas
 [2]: https://wiki.python.org/moin/HandlingExceptions
 [3]: http://docs.python.org/2/library/exceptions.html#exceptions.KeyboardInterrupt