Py3: Replace six.string_types with str

In Python 3, six.string_types is just an alias for str.

See: https://pagure.io/freeipa/issue/7715
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>

ipapython/kernel_keyring.py

@@ -20,7 +20,6 @@
 from __future__ import absolute_import
 
 import os
-import six
 
 from ipapython.ipautil import run
 from ipaplatform.paths import paths
@@ -51,7 +50,7 @@ def get_real_key(key):
     One cannot request a key based on the description it was created with
     so find the one we're looking for.
     """
-    assert isinstance(key, six.string_types)
+    assert isinstance(key, str)
     result = run([paths.KEYCTL, 'search', KEYRING, KEYTYPE, key],
                  raiseonerr=False, capture_output=True)
     if result.returncode:
@@ -66,7 +65,7 @@ def get_persistent_key(key):
 
     Assert when key is not a string-type.
     """
-    assert isinstance(key, six.string_types)
+    assert isinstance(key, str)
     result = run([paths.KEYCTL, 'get_persistent', KEYRING, key],
                  raiseonerr=False, capture_output=True)
     if result.returncode:
@@ -91,7 +90,7 @@ def has_key(key):
     """
     Returns True/False whether the key exists in the keyring.
     """
-    assert isinstance(key, six.string_types)
+    assert isinstance(key, str)
     try:
         get_real_key(key)
         return True
@@ -105,7 +104,7 @@ def read_key(key):
 
     Use pipe instead of print here to ensure we always get the raw data.
     """
-    assert isinstance(key, six.string_types)
+    assert isinstance(key, str)
     real_key = get_real_key(key)
     result = run([paths.KEYCTL, 'pipe', real_key], raiseonerr=False,
                  capture_output=True)
@@ -119,7 +118,7 @@ def update_key(key, value):
     """
     Update the keyring data. If they key doesn't exist it is created.
     """
-    assert isinstance(key, six.string_types)
+    assert isinstance(key, str)
     assert isinstance(value, bytes)
     if has_key(key):
         real_key = get_real_key(key)
@@ -135,7 +134,7 @@ def add_key(key, value):
     """
     Add a key to the kernel keyring.
     """
-    assert isinstance(key, six.string_types)
+    assert isinstance(key, str)
     assert isinstance(value, bytes)
     if has_key(key):
         raise ValueError('key %s already exists' % key)
@@ -149,7 +148,7 @@ def del_key(key):
     """
     Remove a key from the keyring
     """
-    assert isinstance(key, six.string_types)
+    assert isinstance(key, str)
     real_key = get_real_key(key)
     result = run([paths.KEYCTL, 'unlink', real_key, KEYRING],
                  raiseonerr=False)