From b8a845073bd164ea245e632643431ccef90a5ed6 Mon Sep 17 00:00:00 2001
From: Patrick Shriwise <pshriwise@gmail.com>
Date: Sun, 7 Oct 2018 17:21:48 -0500
Subject: [PATCH] Using travis environment variable to check Python version.

---
 tools/ci/travis-install.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/ci/travis-install.sh b/tools/ci/travis-install.sh
index db8d1ca5a..cc707d861 100755
--- a/tools/ci/travis-install.sh
+++ b/tools/ci/travis-install.sh
@@ -26,8 +26,8 @@ python tools/ci/travis-install.py
 # Install Python API in editable mode
 pip install -e .[test]
 
-a=$(dpkg --compare-versions $(python --version | cut -d" " -f 2) lt 3.7.0)
-if [ $a -eq 0 ]; then
+# conditionally install vtk
+if [ $TRAVIS_PYTHON_VERSION -ne 3.7 ]; then
     pip install -e .[vtk]
 fi