Stop contourf interpolating values
Given that the question has not been updated to clearify the actual problem, I will simply answer the question as it is:
No, there is no way that contour would not interpolate because the whole concept of a contour plot is to interpolate the values.
I am trying to plot some 2D values in a Basemap with contourf (matplotlib).
However, contourf by default interpolates intermediate values and gives a smoother image of the data. 
Is there any way to make contourf to stop interpolating between values?
I have tried by adding the keyword argument interpolation='nearest' but contourf does not use it. 
Other option would be to use imshow, but there are some functionalities of contourf that do not work with imshow. 
I am using python 3.6.3 and matplotlib 2.1.2