REL: v3.1.0 The first release of the v3.1 series This version of Matplotlib support Python 3.6+ Highlights of this release include: - A helper method for scatter legends - Secondary axis support (ex, degrees and radians) - A concise date formatter - No longer requires a framework build of Python to use OSX backend - Major and minor ticks will no longer collide by default - A progress callback for animations - mplot3D is always registered - deprecated mlab functions have been removed - Many function calls have become stricter about invalid or ignored input