Merge pull request #12500 from Carreau/pylab-deprecate

Pylab deprecate

IPython/core/magics/pylab.py

@@ -154,6 +154,7 b' class PylabMagics(Magics):'
 
         gui, backend, clobbered = self.shell.enable_pylab(args.gui, import_all=import_all)
         self._show_matplotlib_backend(args.gui, backend)
+        print ("%pylab is deprecated, use %matpltolib inline and import the required libraries.")
         print ("Populating the interactive namespace from numpy and matplotlib")
         if clobbered:
             warn("pylab import has clobbered these variables: %s"  % clobbered +