matplotlib ignores CocoaAgg backend in matplotlibrc

I have the CocoaAgg backend specified in matplotlibrc in ~/.matplotlib/ as:

backend : CocoaAgg

However, when I plot, matplotlib uses the TkAgg backend in spite of this.

···

--
Christopher J. Fonnesbeck
+ Fish & Wildlife Research Institute (FWC)
+ 727.235.5570