Unpickling a tree containing a SymlinkNode causes a RecursionError

[btwahl]

For context, I'm attempting to use pickle instead of the exporters provided by anytree because I have some objects that are not JSON serializable. The following is a simple example that duplicates the issue I am experiencing.

Pickling and unpickling a tree that does not contain any SymlinkNode nodes does not cause any issues and works as expected:

import pickle
from anytree import Node, SymlinkNode, RenderTree

root = Node(name='root')
a = Node(name='a', parent=root)
b = Node(name='b', parent=a)
# c = SymlinkNode(target=b, parent=a)

for pre, _, node in RenderTree(root):
    print(f'{pre}{node.name}')

with open('testtest.pkl', 'wb') as f:
    pickle.dump(root, f)

with open('testtest.pkl', 'rb') as f:
    root = pickle.load(f)

for pre, _, node in RenderTree(root):
    print(f'{pre}{node.name}')

As expected, output is:

root
└── a
    └── b
root
└── a
    └── b

However, once a SymlinkNode is introduced, there is a RecursionError:

import pickle
from anytree import Node, SymlinkNode, RenderTree

root = Node(name='root')
a = Node(name='a', parent=root)
b = Node(name='b', parent=a)
c = SymlinkNode(target=b, parent=a)

for pre, _, node in RenderTree(root):
    print(f'{pre}{node.name}')

with open('testtest.pkl', 'wb') as f:
    pickle.dump(root, f)

with open('testtest.pkl', 'rb') as f:
    root = pickle.load(f)

for pre, _, node in RenderTree(root):
    print(f'{pre}{node.name}')

Now, output is:

root
└── a
    ├── b
    └── b
Traceback (most recent call last):
  File "c:/Users/b/Documents/repos/test_space/test.py", line 18, in <module>
    root = pickle.load(f)
  File "C:\Users\b\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 52, in __getattr__      
    return getattr(self.target, name)
  File "C:\Users\b\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 52, in __getattr__      
    return getattr(self.target, name)
  File "C:\Users\b\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 52, in __getattr__      
    return getattr(self.target, name)
  [Previous line repeated 329 more times]
  File "C:\Users\b\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 49, in __getattr__
    if name in ('_NodeMixin__parent', '_NodeMixin__children'):
RecursionError: maximum recursion depth exceeded in comparison

[c0fec0de]

i will take care physhics <notifications@github.com> schrieb am Mo., 13. Juli 2020, 00:09:

…

For context, I'm attempting to use pickle instead of the exporters provided by anytree because I have some objects that are not JSON serializable. The following is a simple example that duplicates the issue I am experiencing. Pickling and unpickling a tree that does not contain any SymlinkNode nodes does not cause any issues and works as expected: import pickle from anytree import Node, SymlinkNode, RenderTree root = Node(name='root') a = Node(name='a', parent=root) b = Node(name='b', parent=a) # c = SymlinkNode(target=b, parent=a) for pre, _, node in RenderTree(root): print(f'{pre}{node.name}') with open('testtest.pkl', 'wb') as f: pickle.dump(root, f) with open('testtest.pkl', 'rb') as f: root = pickle.load(f) for pre, _, node in RenderTree(root): print(f'{pre}{node.name}') As expected, output is: root └── a └── b root └── a └── b However, once a SymlinkNode is introduced, there is a RecursionError: import pickle from anytree import Node, SymlinkNode, RenderTree root = Node(name='root') a = Node(name='a', parent=root) b = Node(name='b', parent=a) c = SymlinkNode(target=b, parent=a) for pre, _, node in RenderTree(root): print(f'{pre}{node.name}') with open('testtest.pkl', 'wb') as f: pickle.dump(root, f) with open('testtest.pkl', 'rb') as f: root = pickle.load(f) for pre, _, node in RenderTree(root): print(f'{pre}{node.name}') Now, output is: root └── a ├── b └── b Traceback (most recent call last): File "c:/Users/bwahl/Documents/repos/test_space/test.py", line 18, in <module> root = pickle.load(f) File "C:\Users\bwahl\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 52, in __getattr__ return getattr(self.target, name) File "C:\Users\bwahl\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 52, in __getattr__ return getattr(self.target, name) File "C:\Users\bwahl\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 52, in __getattr__ return getattr(self.target, name) [Previous line repeated 329 more times] File "C:\Users\bwahl\AppData\Local\Programs\Python\Python36-32\lib\site-packages\anytree\node\symlinknodemixin.py", line 49, in __getattr__ if name in ('_NodeMixin__parent', '_NodeMixin__children'): RecursionError: maximum recursion depth exceeded in comparison — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#138>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AE77IH5QUWYNPQIMAGOU3F3R3IX75ANCNFSM4OX76GEQ> .

[kylewhite21]

Can be fixed by adding an elif block to the method here:

    def __getattr__(self, name):
        if name in ('_NodeMixin__parent', '_NodeMixin__children'):
            return super(SymlinkNodeMixin, self).__getattr__(name)
        elif name == '__setstate__':
            raise AttributeError(name)
        else:
            return getattr(self.target, name)