retain compatibility with python2

tools/python/log2txt.py

@@ -10,6 +10,8 @@
 #                    if no columns listed, all columns are included
 # Author:  Steve Plimpton (Sandia), sjplimp at sandia.gov
 
+from __future__ import print_function
+
 import sys,os
 path = os.environ["LAMMPS_PYTHON_TOOLS"]
 sys.path.append(path)

tools/python/pizza/log.py

@@ -6,6 +6,8 @@
 # certain rights in this software.  This software is distributed under
 # the GNU General Public License.
 
+from __future__ import print_function
+
 # log tool
 
 oneline = "Read LAMMPS log files and extract thermodynamic data"