Make all Python scripts compatible with Python 2 and 3

It would be nice to upgrade completely to Python 3, but this may
create problems at SLAC because psana only supports Python 2 (Python 3
is available, but means that users have to jump through hoops to run
a simple CrystFEL script).  None of our scripts do anything complicated,
so they can all be compatible with both so far.

If anyone adds a script which requires a particular version, make sure
to specify the version in the first line, consistent with PEP 394.

1 files changed, 10 insertions, 3 deletions

diff --git a/scripts/crystal-frame-number b/scripts/crystal-frame-number
index b3ed3f1f..883abb81 100755
--- a/scripts/crystal-frame-number
+++ b/scripts/crystal-frame-number
@@ -1,6 +1,13 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-
+#
+# Show sequence numbers of crystals and frames
+#
+# Copyright © 2015-2017 Deutsches Elektronen-Synchrotron DESY,
+#                       a research centre of the Helmholtz Association.
+#
+# Author:
+#    2015-2017 Thomas White <taw@physics.org>
 
 import sys
 
@@ -16,9 +23,9 @@ while True:
     if fline.find("Image filename") != -1:
         frame_number += 1
         fn = fline.split(': ')[1].split(' ')[0].rstrip("\r\n")
-	print 'Frame %i: %s' % (frame_number, fn)
+        print('Frame {}: {}'.format(frame_number, fn))
     if fline.find("diffraction_resolution_limit") != -1:
         crystal_number += 1
-	print '  Crystal %i: %s' % (crystal_number, fline.rstrip("\r\n"))
+        print('  Crystal {}: {}'.format(crystal_number, fline.rstrip("\r\n")))
 
 f.close()