pywrap and fix tests

Author: Tieqiong

src/diffpy/pdffit2/output.py

@@ -38,5 +38,13 @@ def redirect_stdout(dst):
     stdout = dst
     return
 
+def restore_stdout():
+    """Restore the standard output."""
+    from diffpy.pdffit2.pdffit2 import restore_stdout
+
+    restore_stdout()
+    global stdout
+    return
+
 
 #  End of file

tests/conftest.py

@@ -45,6 +45,7 @@ def _capture(f, *args, **kwargs):
             f(*args, **kwargs)
         finally:
             diffpy.pdffit2.redirect_stdout(savestdout)
+            diffpy.pdffit2.output.restore_stdout()
         return fp.getvalue()
 
     return _capture