From 9e8ae80d2d2d12d27a1aaadf471fec730fbbba27 Mon Sep 17 00:00:00 2001
From: Ray Speth <speth@mit.edu>
Date: Thu, 27 Mar 2014 01:29:39 +0000
Subject: [PATCH] [ctml_writer] Direct error/debug messages to stderr

Since stdout may be used for writing the actual output file, direct all error
and debug messages to stderr, so that they can be shown to the user when
ctml_writer is invoked via ct2ctml_string.
---
 interfaces/cython/cantera/ctml_writer.py | 52 +++++++++++++-----------
 1 file changed, 29 insertions(+), 23 deletions(-)

diff --git a/interfaces/cython/cantera/ctml_writer.py b/interfaces/cython/cantera/ctml_writer.py
index 8b386f142..3ba93ff99 100644
--- a/interfaces/cython/cantera/ctml_writer.py
+++ b/interfaces/cython/cantera/ctml_writer.py
@@ -20,14 +20,18 @@ from __future__ import print_function
 
 import sys
 
+def _printerr(*args):
+    # All debug and error output should go to stderr
+    print(*args, file=sys.stderr)
+
 class CTI_Error(Exception):
     """Exception raised if an error is encountered while
     parsing the input file.
     @ingroup pygroup"""
     def __init__(self, msg):
-        print('\n\n***** Error parsing input file *****\n\n')
-        print(msg)
-        print()
+        _printerr('\n\n***** Error parsing input file *****\n\n')
+        _printerr(msg)
+        _printerr()
 
 
 
@@ -993,12 +997,13 @@ class Arrhenius(rate_expression):
                             "temperature exponent. Specify one or the other.")
         elif n is not None and b == 0.0:
             b = n
-            print("Warning: Usage of n to specify the temperature exponent is "
-                  "deprecated and will be removed in a future version. Use b "
-                  "to specify the temperature exponent by keyword. Please check "
-                  "your cti file for places where the temperature exponent of "
-                  "the reaction rate is set by n = XXX and change them to "
-                  "b = XXX.")
+            _printerr(
+                "Warning: Usage of n to specify the temperature exponent is "
+                "deprecated and will be removed in a future version. Use b "
+                "to specify the temperature exponent by keyword. Please check "
+                "your cti file for places where the temperature exponent of "
+                "the reaction rate is set by n = XXX and change them to "
+                "b = XXX.")
 
         self._c = [A, b, E]
         self._type = rate_type
@@ -1887,9 +1892,9 @@ class ideal_gas(phase):
         self._kin = kinetics
         self._tr = transport
         if self.debug:
-            print('Read ideal_gas entry '+self._name)
+            _printerr('Read ideal_gas entry '+self._name)
             try:
-                print('in file '+__name__)
+                _printerr('in file '+__name__)
             except:
                 pass
 
@@ -2590,6 +2595,7 @@ class Lindemann(object):
 validate()
 
 def convert(filename, outName=None):
+
     import os
     base = os.path.basename(filename)
     root, _ = os.path.splitext(base)
@@ -2602,16 +2608,16 @@ def convert(filename, outName=None):
         # Show more context than the default SyntaxError message
         # to help see problems in multi-line statements
         text = open(filename, 'rU').readlines()
-        print('%s in "%s" on line %i:\n' % (err.__class__.__name__,
-                                            err.filename,
-                                            err.lineno))
-        print('|  Line |')
+        _printerr('%s in "%s" on line %i:\n' % (err.__class__.__name__,
+                                                err.filename,
+                                                err.lineno))
+        _printerr('|  Line |')
         for i in range(max(err.lineno-6, 0),
                        min(err.lineno+3, len(text))):
-            print('| % 5i |' % (i+1), text[i].rstrip())
+            _printerr('| % 5i |' % (i+1), text[i].rstrip())
             if i == err.lineno-1:
-                print(' '* (err.offset+9) + '^')
-        print()
+                _printerr(' '* (err.offset+9) + '^')
+        _printerr()
         sys.exit(3)
     except Exception as err:
         import traceback
@@ -2621,16 +2627,16 @@ def convert(filename, outName=None):
         lineno = tb[-1][1]
         if tb[-1][0] == filename:
             # Error in input file
-            print('%s on line %i of %s:' % (err.__class__.__name__, lineno, filename))
-            print(err)
-            print('\n| Line |')
+            _printerr('%s on line %i of %s:' % (err.__class__.__name__, lineno, filename))
+            _printerr(err)
+            _printerr('\n| Line |')
 
             for i in range(max(lineno-6, 0),
                            min(lineno+3, len(text))):
                 if i == lineno-1:
-                    print('> % 4i >' % (i+1), text[i].rstrip())
+                    _printerr('> % 4i >' % (i+1), text[i].rstrip())
                 else:
-                    print('| % 4i |' % (i+1), text[i].rstrip())
+                    _printerr('| % 4i |' % (i+1), text[i].rstrip())
         else:
             # Error in ctml_writer or elsewhere
             traceback.print_exc()