Python 3.7.6
Matplotlib 3.2.1
When running
ax.contour(x,y,z,levels=[1.])
and a contour level of 1 does not exist, it was still drawing a contour. I take it that it was treating levels as an int for the number of levels to draw. I ended up only allowing the call to contour after I check if the max value of the z array was greater than my level. Maybe I am making a mistake by only having 1 contour level, but i thought the default behavior was to assume numeric levels when in an array/list.
Im due for an upgrade so maybe this problem has already been addressed.
Thanks for reading
jimmyc