fix recursion problem on example, linting

examples/maybe.py

 import builtins
-import ctypes
 import random
 from happen.happen import keyword_patcher
 
+
 class Maybe:
     def __bool__(self):
         return random.choice((True, False))
+
     def __repr__(self):
         return f"Maybe?"
+
     def __str__(self):
         return repr(self)
-    
+
+
 Maybe = Maybe()
-keyword_patcher(('Maybe',), '__main__')
+keyword_patcher(("Maybe",), "__main__")
+original_isinstance = isinstance
+
 
 def check(a, b):
     if a is Maybe and b is bool:
         return True
-    return isinstance(a, b)
-
-builtins.isinstance = check
-
-
-
-
-
-
-
+    return original_isinstance(a, b)
 
 
+builtins.isinstance = check

examples/test.py

 from maybe import Maybe
 
 print(isinstance(Maybe, bool))
+print(isinstance(int, bool))

happen/happen.py

-import sys
 import ast
 import random
+import sys
+
 
 class KeywordListener(ast.NodeTransformer):
     def __init__(self, keywords, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.keywords = keywords
-        
+
     def visit_Delete(self, node):
         if any(filter(lambda target: target.id in self.keywords, node.targets)):
             raise SyntaxError("can't delete keyword")
-        
+
         return node
-        
+
     def visit_Assign(self, node):
         if any(filter(lambda target: target.id in self.keywords, node.targets)):
             raise SyntaxError("can't assign to keyword")
-            
+
         return node
-        
+
+
 def keyword_patcher(keywords, name, *args, **kwargs):
     module = __import__(name, *args, **kwargs)
-    if module.__name__ != '__main__' and not hasattr(module, '__file__'):
+    if module.__name__ != "__main__" and not hasattr(module, "__file__"):
         return module
-    
+
     tree = ast.parse(
-        ''.join(
-            open(
-                sys.modules[name].__file__.replace('pyc', 'py'),
-                'r'
-            ).readlines()
-        )
+        "".join(open(sys.modules[name].__file__.replace("pyc", "py"), "r").readlines())
     )
     tree = KeywordListener(keywords).visit(tree)
     ast.fix_missing_locations(tree)