pyzfs python3 support (4): compatible changes

These changes are slightly less idomatic python, but
are valid and efficient in both python 2 and 3.

Signed-off-by: Antonio Russo <antonio.e.russo@gmail.com>
Requires-builders: none

contrib/pyzfs/libzfs_core/_error_translation.py

@@ -272,7 +272,8 @@ def _map(ret, name):
 def lzc_release_translate_errors(ret, errlist, holds):
     if ret == 0:
         return
-    for _, hold_list in holds.items():
+    for snap in holds:
+        hold_list = holds[snap]
         if not isinstance(hold_list, list):
             raise lzc_exc.TypeError('holds must be in a list')
 
@@ -716,7 +717,8 @@ def _handle_err_list(ret, errlist, names, exception, mapper):
     else:
         errors = []
         suppressed_count = errlist.pop('N_MORE_ERRORS', 0)
-        for name, err in errlist.items():
+        for name in errlist:
+            err = errlist[name]
             errors.append(mapper(err, name))
 
     raise exception(errors, suppressed_count)

contrib/pyzfs/libzfs_core/_libzfs_core.py

@@ -486,7 +486,7 @@ def lzc_hold(holds, fd=None):
     errors.lzc_hold_translate_errors(ret, errlist, holds, fd)
     # If there is no error (no exception raised by _handleErrList), but errlist
     # is not empty, then it contains missing snapshots.
-    assert all(x == errno.ENOENT for x in errlist.values())
+    assert all(errlist[x] == errno.ENOENT for x in errlist)
     return list(errlist.keys())
 
 
@@ -522,7 +522,8 @@ def lzc_release(holds):
     '''
     errlist = {}
     holds_dict = {}
-    for snap, hold_list in holds.items():
+    for snap in holds:
+        hold_list = holds[snap]
         if not isinstance(hold_list, list):
             raise TypeError('holds must be in a list')
         holds_dict[snap] = {hold: None for hold in hold_list}
@@ -532,7 +533,7 @@ def lzc_release(holds):
     errors.lzc_release_translate_errors(ret, errlist, holds)
     # If there is no error (no exception raised by _handleErrList), but errlist
     # is not empty, then it contains missing snapshots and tags.
-    assert all(x == errno.ENOENT for x in errlist.values())
+    assert all(errlist[x] == errno.ENOENT for x in errlist)
     return list(errlist.keys())
 
 
@@ -1882,7 +1883,7 @@ def lzc_get_props(name):
         mountpoint_val = '/' + name
     else:
         mountpoint_val = None
-    result = {k: v['value'] for k, v in result.items()}
+    result = {k: result[k]['value'] for k in result}
     if 'clones' in result:
         result['clones'] = list(result['clones'].keys())
     if mountpoint_val is not None: