make docker a python (2+3) script

Dockerfile

@@ -1,11 +0,0 @@
-from python:3
-RUN pip install --upgrade pip && pip install \
-  ply \
-  prompt-toolkit \
-  pygments
-RUN mkdir /xonsh
-WORKDIR /xonsh
-ADD ./ ./
-RUN python setup.py install
-CMD /usr/bin/env xonsh
-ENV XONSH_COLOR_STYLE "paraiso-dark"

docker.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+import sys 
+import subprocess
+import os
+
+pythonVersion = '3.5'
+ptkVersion = '1.00'
+
+if len(sys.argv) > 1:
+    pythonVersion = sys.argv[1]
+    if len(sys.argv) > 2:
+        ptkVersion = sys.argv[2]
+
+print('Building and runing Xonsh')
+print('Using python ', pythonVersion)
+print('Using prompt-toolkit ', ptkVersion)
+
+dockerFile = 'from python:'+pythonVersion + '\n'
+dockerFile += 'RUN pip install --upgrade pip && pip install \\\n'
+dockerFile += '  ply \\\n'
+dockerFile += '  prompt-toolkit=='+ptkVersion+ ' \\\n'
+dockerFile += '  pygments\n'
+dockerFile += 'RUN mkdir /xonsh\n'
+dockerFile += 'WORKDIR /xonsh\n'
+dockerFile += 'CMD /usr/bin/env xonsh\n'
+dockerFile += 'ENV XONSH_COLOR_STYLE "paraiso-dark\n'
+dockerFile += 'ADD ./ ./\n'
+dockerFile += 'RUN python setup.py install\n'
+
+with open('./Dockerfile', 'w+') as f:
+    f.write(dockerFile)
+
+subprocess.call(['docker', 'build', '-t' , 'xonsh', '.'])
+os.remove('./Dockerfile')
+subprocess.call(['docker', 'run', '-ti' , 'xonsh'])
+
+