From f44a5e33bf8d194931f200c7d84fadc5755091c9 Mon Sep 17 00:00:00 2001
From: Malte Persike <malte.persike@gmail.com>
Date: Wed, 19 Sep 2018 13:11:38 +0200
Subject: [PATCH] ENH: ExperimentHandler.saveAsWideText() has a new parameter
 "sortedColumns" which has header names sorted alphabetically when storing
 data in a text file.

This guarantees a predictable order of columns in the stored csv/tsv files.
---
 psychopy/data/experiment.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/psychopy/data/experiment.py b/psychopy/data/experiment.py
index 5b8178fbbc..7dcc219509 100644
--- a/psychopy/data/experiment.py
+++ b/psychopy/data/experiment.py
@@ -252,7 +252,8 @@ def saveAsWideText(self,
                        matrixOnly=False,
                        appendFile=False,
                        encoding='utf-8',
-                       fileCollisionMethod='rename'):
+                       fileCollisionMethod='rename',
+                       sortColumns=False):
         """Saves a long, wide-format text file, with one line representing
         the attributes and data for a single trial. Suitable for analysis
         in R and SPSS.
@@ -291,6 +292,9 @@ def saveAsWideText(self,
                 Collision method passed to
                 :func:`~psychopy.tools.fileerrortools.handleFileCollision`
 
+            sortColumns:
+                will sort columns alphabetically by header name if True
+
         """
         # set default delimiter if none given
         if delim is None:
@@ -306,6 +310,9 @@ def saveAsWideText(self,
         names.extend(self.dataNames)
         # names from the extraInfo dictionary
         names.extend(self._getExtraInfo()[0])
+        # sort names if requested
+        if sortColumns:
+            names.sort()
         # write a header line
         if not matrixOnly:
             for heading in names: