Check for correct string class

Use python-six and check against correct string class on both Python 2
and Python 3.

Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

pungi.spec

@@ -18,6 +18,7 @@ BuildRequires:  python-enum34
 BuildRequires:  python2-dnf
 BuildRequires:  python2-multilib
 BuildRequires:  python2-libcomps
+BuildRequires:  python2-six
 
 Requires:       createrepo >= 0.4.11
 Requires:       yum => 3.4.3-28
@@ -46,6 +47,7 @@ Requires:       python-enum34
 Requires:       python2-dnf
 Requires:       python2-multilib
 Requires:       python2-libcomps
+Requires:       python2-six
 
 BuildArch:      noarch
 

pungi/checks.py

@@ -40,8 +40,9 @@ from __future__ import print_function
 import contextlib
 import os.path
 import platform
-import jsonschema
 import re
+import jsonschema
+import six
 from kobo.shortcuts import force_list
 from productmd.composeinfo import COMPOSE_TYPES
 

pungi/createiso.py

@@ -4,6 +4,7 @@ from __future__ import print_function
 
 import os
 import pipes
+import six
 from collections import namedtuple
 
 from .wrappers import iso
@@ -27,7 +28,7 @@ def quote(str):
 
 def emit(f, cmd):
     """Print line of shell code into the stream."""
-    if isinstance(cmd, basestring):
+    if isinstance(cmd, six.string_types):
         print(cmd, file=f)
     else:
         print(' '.join([quote(x) for x in cmd]), file=f)

pungi/wrappers/scm.py

@@ -19,6 +19,7 @@ import os
 import shutil
 import pipes
 import glob
+import six
 
 import kobo.log
 from kobo.shortcuts import run, force_list
@@ -226,7 +227,7 @@ def get_file_from_scm(scm_dict, target_path, logger=None):
         >>> get_file_from_scm(scm_dict, target_path)
         ['/tmp/path/share/variants.dtd']
     """
-    if isinstance(scm_dict, basestring):
+    if isinstance(scm_dict, six.string_types):
         scm_type = "file"
         scm_repo = None
         scm_file = os.path.abspath(scm_dict)
@@ -279,7 +280,7 @@ def get_dir_from_scm(scm_dict, target_path, logger=None):
         >>> get_dir_from_scm(scm_dict, target_path)
         ['/tmp/path/share/variants.dtd', '/tmp/path/share/rawhide-fedora.ks', ...]
     """
-    if isinstance(scm_dict, basestring):
+    if isinstance(scm_dict, six.string_types):
         scm_type = "file"
         scm_repo = None
         scm_dir = os.path.abspath(scm_dict)

setup.py

@@ -61,6 +61,7 @@ setup(
         "lockfile",
         "lxml",
         "productmd",
+        "six",
         ],
     tests_require = [
         "mock",