BUG fixed printing of convergence message in minimize_scalar in scipy…

…/optimize (scipy#8273)

followed suggestion by dlax in scipy#8273 and converted disp from bool to int
also corrected docstring of _minimize_scalar_bounded (disp is int instead of bool)

scipy/optimize/_minimize.py

@@ -655,6 +655,11 @@ def minimize_scalar(fun, bracket=None, bounds=None, args=(),
         if bounds is None:
             raise ValueError('The `bounds` parameter is mandatory for '
                              'method `bounded`.')
+        # replace boolean "disp" option, if specified, by an integer value, as
+        # expected by _minimize_scalar_bounded()
+        disp = options.get('disp')
+        if isinstance(disp, bool):
+            options['disp'] = 2 * int(disp)
         return _minimize_scalar_bounded(fun, bounds, args, **options)
     elif meth == 'golden':
         return _minimize_scalar_golden(fun, bracket, args, **options)

scipy/optimize/optimize.py

@@ -1728,8 +1728,12 @@ def _minimize_scalar_bounded(func, bounds, args=(),
     -------
     maxiter : int
         Maximum number of iterations to perform.
-    disp : bool
-        Set to True to print convergence messages.
+    disp: int, optional
+        If non-zero, print messages.
+            0 : no message printing.
+            1 : non-convergence notification messages only.
+            2 : print a message on convergence too.
+            3 : print iteration results.
     xatol : float
         Absolute error in solution `xopt` acceptable for convergence.