diff --git a/pynspect/jpath.py b/pynspect/jpath.py
index 9e2b924c9ebd8718937310cd84f933f5bd88082c..84f237a3083a4056cb7e973dd53931e26b067c29 100644
--- a/pynspect/jpath.py
+++ b/pynspect/jpath.py
@@ -242,7 +242,7 @@ def jpath_parse_c(jpath):
     references to internal cache. Treat the returned values as read only, or
     suffer the consequences.
     """
-    if not jpath in _JPATH_CACHE:
+    if jpath not in _JPATH_CACHE:
         _JPATH_CACHE[jpath] = jpath_parse(jpath)
     return _JPATH_CACHE[jpath]
 
@@ -294,7 +294,7 @@ def jpath_values(structure, jpath):
             # Process unindexed nodes.
             else:
                 # Skip the node, if the key does not exist.
-                if not key in node:
+                if key not in node:
                     continue
 
                 # Handle list values - expand them.
@@ -338,7 +338,7 @@ def jpath_exists(structure, jpath):
     :rtype: bool
     """
     result = jpath_value(structure, jpath)
-    if not result is None:
+    if result is not None:
         return True
     return False
 
@@ -375,7 +375,7 @@ def jpath_set(structure, jpath, value, overwrite=True, unique=False):
             idx = chnk['i']
 
             # Automatically create nodes for non-existent keys.
-            if not key in current:
+            if key not in current:
                 current[key] = []
             if not isinstance(current[key], list) and not isinstance(current[key], MutableSequence):
                 raise JPathException("Expected list-like object under structure key '{}'".format(key))
@@ -412,7 +412,7 @@ def jpath_set(structure, jpath, value, overwrite=True, unique=False):
                 except (IndexError, TypeError):
                     # At this point only deal with unique, overwrite does not make
                     # sense, because we would not be here otherwise.
-                    if not unique or not value in current[key]:
+                    if not unique or value not in current[key]:
                         current[key].append(value)
                     else:
                         return RC_VALUE_DUPLICATE
@@ -422,7 +422,7 @@ def jpath_set(structure, jpath, value, overwrite=True, unique=False):
             # Detection of the last JPath chunk - node somewhere in the middle.
             if i != size:
                 # Automatically create nodes for non-existent keys.
-                if not key in current:
+                if key not in current:
                     current[key] = {}
                 if not isinstance(current[key], dict) and not isinstance(current[key], Mapping):
                     raise JPathException("Expected dict-like object under structure key '{}'".format(key))
@@ -431,7 +431,7 @@ def jpath_set(structure, jpath, value, overwrite=True, unique=False):
 
             # Detection of the last JPath chunk - node at the end.
             else:
-                if overwrite or not key in current:
+                if overwrite or key not in current:
                     current[key] = value
                 else:
                     return RC_VALUE_EXISTS
@@ -471,7 +471,7 @@ def jpath_unset(structure, jpath):
                 idx = chnk['i']
 
                 # Skip nodes for non-existent keys.
-                if not key in node:
+                if key not in node:
                     continue
                 if not isinstance(node[key], list) and not isinstance(node[key], MutableSequence):
                     raise JPathException("Expected list-like object under structure key '{}'".format(key))
@@ -507,7 +507,7 @@ def jpath_unset(structure, jpath):
                 # Detection of the last JPath chunk - node somewhere in the middle.
                 if i != size:
                     # Skip nodes for non-existent keys.
-                    if not key in node:
+                    if key not in node:
                         continue
                     if isinstance(node[key], list):
                         nodes_b.extend(node[key])