DeprecationWarnings in Python 2.7

If you're using Python versino 2.7, you may notice that the DeprecationWarning no longer displays. This has been de-activated by default, however, it can be switched back on by, for example, doing the following in iPython 


>>> import warnings 
>>> warnings.simplefilter("always") 

If you now call a deprecated class on purpose, iPython will display the full DeprecationWarning