restore python3 support. this now can run with python 2.7.13 and 3.5.3.

if buildflag:

  # set install directory

  dir = os.path.join(os.path.abspath(dir), "installed-" + version)

  # check to see if an installed kim-api already exists

  # check to see if an installed kim-api already exists and wipe it out.

  if os.path.isdir(dir):

     print("kim-api is already installed at %s" % dir)

     print("Must remove this directory in order to resintall at this location")

     sys.exit()

    print("kim-api is already installed at %s.\nRemoving it for re-install" % dir)

    cmd = "rm -rf %s" % dir

    subprocess.check_output(cmd,shell=True)

  # configure LAMMPS to use kim-api to be installed

  print("Created %s/Makefile.KIM_DIR : using %s" % (thisdir,dir))

  # download entire kim-api tarball

  # try first via urllib

  # if fails (probably due to no SSL support), use wget

  print("Downloading kim-api tarball ...")

  try: geturl(url,"%s/%s.tgz" % (thisdir,version))

  except:

    cmd = "wget %s %s/%s.tgz" % (url,thisdir,version)

    subprocess.check_output(cmd,shell=True)

    if not os.path.isfile("%s/%s.tgz" % (thisdir,version)):

      print("Both urllib and wget command failed to download")

      sys.exit()

  geturl(url,"%s/%s.tgz" % (thisdir,version))

  print("Unpacking kim-api tarball ...")

  cmd = "cd %s; rm -rf %s; tar zxvf %s.tgz" % (thisdir,version,version)

  subprocess.check_output(cmd,shell=True)

  # if fails (probably due to no SSL support), use wget

  print("Downloading item tarball ...")

  url = "https://openkim.org/download/%s.tgz" % addmodelname

  try: geturl(url,"%s/%s.tgz" % (thisdir,addmodelname))

  except:

    cmd = "wget %s %s/%s.tgz" % (url,thisdir,addmodelname)

    txt = subprocess.check_output(cmd,shell=True)

    print(txt[1])

    if not os.path.isfile("%s/%s.tgz" % (thisdir,addmodelname)):

      print("Both urllib.urlretrieve() and wget command failed to download")

      sys.exit()

  geturl(url,"%s/%s.tgz" % (thisdir,addmodelname))

  print("Unpacking item tarball ...")

  cmd = "cd %s; tar zxvf %s.tgz" % (thisdir,addmodelname)

  except subprocess.CalledProcessError as e:

    # Error: but first, check to see if it needs a driver

    firstRunOutput = e.output

    firstRunOutput = e.output.decode()

    cmd = "cd %s/%s; make kim-item-type" % (thisdir,addmodelname)

    txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)

    txt = txt.decode().strip()

    if txt == "ParameterizedModel":

      # Get and install driver

      cmd = "cd %s/%s; make model-driver-name" % (thisdir,addmodelname)

      txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)

      adddrivername = txt

      print("First Installing model driver: %s" % adddrivername)

      adddrivername = txt.decode().strip()

      print("First installing model driver: %s" % adddrivername)

      cmd = "cd %s; python Install.py -a %s" % (thisdir,adddrivername)

      try:

        txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)

        print(e.output)

        sys.exit()

      print(txt)

      # now install the model that needed the driver

      print("Now installing model : %s" % addmodelname)

      cmd = "cd %s; python Install.py -a %s" % (thisdir,addmodelname)

      try:

        txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)

      except subprocess.CalledProcessError as e:

        print(e.output)

        sys.exit()

      print(txt)

      print(txt.decode())

      sys.exit()

    else:

      print(firstRunOutput)