refactor the code of checking the python dependencies

examples/python/check_dependencies.py

@@ -1,4 +1,4 @@
-import logging, sys, inspect, os
+import logging, sys, inspect
 from os.path import dirname, abspath
 from optparse import OptionParser
 
@@ -8,7 +8,7 @@ try:
     from setuptools.command import easy_install
 except ImportError:
     raise ImportError("""setuptools is not installed for \"""" + sys.executable + """\"
-Please follow this link for installing instructions :
+Follow this link for installing instructions :
 https://pypi.python.org/pypi/setuptools
 make sure you use \"""" + sys.executable + """\" during the installation""")
     raise SystemExit
@@ -17,22 +17,23 @@ from pkg_resources import parse_version
 
 def notinstalled(modulename):
 	return modulename + """ could not be imported for \"""" + sys.executable + """\"
-Please set PYTHONPATH to the output of this command \"make print-OR_TOOLS_PYTHONPATH\" before running the examples"""
-
-def wrong_version(module, modulename, minimum_version, installed_version):
-	return """
-You are using """ + modulename + """-""" + installed_version + """ : """ + inspect.getfile(module) + """
-The minimum required version is : """ + minimum_version + """
-Please run \"""" + str(sys.executable) + """ setup.py install --user\" to upgrade
-If the problem persists, then """ + inspect.getfile(module) + """ is binding the newely installed version of """ + modulename + """
-You should either remove it, or use PYTHONPATH to manage your sys.path. If you decide to use PYTHONPATH, do it to run the ortools examples as well.
-Check https://docs.python.org/3/tutorial/modules.html#the-module-search-path from more information."""
+Set PYTHONPATH to the output of this command \"make print-OR_TOOLS_PYTHONPATH\" before running the examples"""
 
 def wrong_module(module_file, modulename):
 	return """
-The python examples are not importing the """ + modulename + """ module from the sources because it's binded by \"""" + module_file + """\".
-Please delete the binding module and rerun this script again. 
-"""
+The python examples are not importing the """ + modulename + """ module from the sources.
+Remove the site-package that contains \"""" + module_file + """\", either manually or by using pip, and rerun this script again."""
+
+def log_error_and_exit(error_message):
+	logging.error(error_message)
+	raise SystemExit
+
+# Returns the n_th parent of file
+def n_dirname(n, file):
+	directory = file
+	for x in xrange(0, n):
+		directory = dirname(directory)
+	return directory
 
 if __name__ == '__main__':
 	parser = OptionParser('Log level')
@@ -49,10 +50,10 @@ if __name__ == '__main__':
 					-1:logging.DEBUG,
 					}[int(options.log)]
 	
-	logging.basicConfig(stream=sys.stdout, level=loglevel)
+	logging.basicConfig(format='[%(levelname)s] %(message)s',stream=sys.stdout, level=loglevel)
 	
 	logging.info("Python path : " + sys.executable)
-	logging.info("Python version : " + sys.version + "\n")
+	logging.info("Python version : " + sys.version)
 
 	#try to import ortools
 	try:
@@ -63,24 +64,22 @@ if __name__ == '__main__':
 
 	#check if we're using ortools from the sources or it's binded by pypi's module
 	ortools_module_file = inspect.getfile(ortools)
-	ortools_module_path = dirname(dirname(dirname(ortools_module_file)))
-	ortools_project_path = dirname(dirname(dirname(abspath(inspect.getfile(inspect.currentframe())))))
+	ortools_module_path = n_dirname(2, ortools_module_file)
+	ortools_project_path = n_dirname(3, abspath(inspect.getfile(inspect.currentframe())))
 	try:
 		if(ortools_module_path == ortools_project_path):
 			logging.info("Good! The python examples are importing the ortools module from the sources. The imported module is : " + inspect.getfile(ortools))
 		else:
 			raise Exception
 	except (Exception):
-		logging.error(wrong_module(ortools_module_file, "ortools"))
-		raise SystemExit
+		log_error_and_exit(wrong_module(ortools_module_file, "ortools"))
 
 	#try to import protobuf
 	try:
 		import google.protobuf
 		logging.info("Protobuf is imported from " + inspect.getfile(google.protobuf))
 	except ImportError:
-	    logging.error (notinstalled("protobuf"))
-	    raise SystemExit
+	    log_error_and_exit(notinstalled("protobuf"))
 
 	# Check if python can load the libraries' modules
 	# this is useful when the library architecture is not compatbile with the python executable,