From 169f287381d3ffba63d1bc1564fffbdf5b4c3e6a Mon Sep 17 00:00:00 2001
From: PythonFZ <fabian.zills@web.de>
Date: Thu, 29 Jun 2023 11:04:17 +0200
Subject: [PATCH 1/2] add custom exceptions

---
 tests/test_err_msg.py | 20 ++++++++++++++++++++
 znflow/__init__.py    |  2 ++
 znflow/base.py        | 10 ++++++++++
 znflow/exceptions.py  |  4 ++++
 4 files changed, 36 insertions(+)
 create mode 100644 tests/test_err_msg.py
 create mode 100644 znflow/exceptions.py

diff --git a/tests/test_err_msg.py b/tests/test_err_msg.py
new file mode 100644
index 0000000..4fad7ed
--- /dev/null
+++ b/tests/test_err_msg.py
@@ -0,0 +1,20 @@
+import znflow
+import dataclasses
+import pytest
+
+@dataclasses.dataclass
+class ComputeMean(znflow.Node):
+    x: float
+    y: float
+    
+    results: float = None
+    
+    def run(self):
+        self.results = (self.x + self.y) / 2
+
+
+def test_attribute_access():
+    with znflow.DiGraph() as graph:
+        n1 = ComputeMean(2, 8)
+        with pytest.raises(znflow.exceptions.ConnectionAttributeError):
+            n1.x.data
diff --git a/znflow/__init__.py b/znflow/__init__.py
index 533d87e..2c621cc 100644
--- a/znflow/__init__.py
+++ b/znflow/__init__.py
@@ -16,6 +16,7 @@
 from znflow.graph import DiGraph
 from znflow.node import Node, nodify
 from znflow.visualize import draw
+from znflow import exceptions
 
 __version__ = importlib.metadata.version(__name__)
 
@@ -31,6 +32,7 @@
     "Property",
     "CombinedConnections",
     "combine",
+    "exceptions",
 ]
 
 with contextlib.suppress(ImportError):
diff --git a/znflow/base.py b/znflow/base.py
index 5f36dc3..590284f 100644
--- a/znflow/base.py
+++ b/znflow/base.py
@@ -3,7 +3,9 @@
 import contextlib
 import dataclasses
 import typing
+from typing import Any
 from uuid import UUID
+from znflow import exceptions
 
 
 @contextlib.contextmanager
@@ -177,6 +179,14 @@ def result(self):
         else:
             result = self.instance
         return result[self.item] if self.item else result
+    
+    def __getattribute__(self, __name: str) -> Any:
+        try:
+            return super().__getattribute__(__name)
+        except AttributeError as e:
+            raise exceptions.ConnectionAttributeError(
+                "Connection does not support further attributes to its result."
+            ) from e
 
 
 @dataclasses.dataclass(frozen=True)
diff --git a/znflow/exceptions.py b/znflow/exceptions.py
new file mode 100644
index 0000000..e486076
--- /dev/null
+++ b/znflow/exceptions.py
@@ -0,0 +1,4 @@
+"""ZnFlow exceptions."""
+
+class ConnectionAttributeError(AttributeError):
+    """Raised when a connection attribute is not found."""

From f409e7377c6514394d702a4a847164a3229aa931 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Wed, 12 Jul 2023 12:19:22 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 tests/test_err_msg.py | 11 +++++++----
 znflow/__init__.py    |  2 +-
 znflow/base.py        |  3 ++-
 znflow/exceptions.py  |  1 +
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/tests/test_err_msg.py b/tests/test_err_msg.py
index 4fad7ed..57115b6 100644
--- a/tests/test_err_msg.py
+++ b/tests/test_err_msg.py
@@ -1,20 +1,23 @@
-import znflow
 import dataclasses
+
 import pytest
 
+import znflow
+
+
 @dataclasses.dataclass
 class ComputeMean(znflow.Node):
     x: float
     y: float
-    
+
     results: float = None
-    
+
     def run(self):
         self.results = (self.x + self.y) / 2
 
 
 def test_attribute_access():
-    with znflow.DiGraph() as graph:
+    with znflow.DiGraph():
         n1 = ComputeMean(2, 8)
         with pytest.raises(znflow.exceptions.ConnectionAttributeError):
             n1.x.data
diff --git a/znflow/__init__.py b/znflow/__init__.py
index 2c621cc..5d3c8f8 100644
--- a/znflow/__init__.py
+++ b/znflow/__init__.py
@@ -4,6 +4,7 @@
 import logging
 import sys
 
+from znflow import exceptions
 from znflow.base import (
     CombinedConnections,
     Connection,
@@ -16,7 +17,6 @@
 from znflow.graph import DiGraph
 from znflow.node import Node, nodify
 from znflow.visualize import draw
-from znflow import exceptions
 
 __version__ = importlib.metadata.version(__name__)
 
diff --git a/znflow/base.py b/znflow/base.py
index 4776a16..6631965 100644
--- a/znflow/base.py
+++ b/znflow/base.py
@@ -5,6 +5,7 @@
 import typing
 from typing import Any
 from uuid import UUID
+
 from znflow import exceptions
 
 
@@ -184,7 +185,7 @@ def result(self):
         else:
             result = self.instance
         return result[self.item] if self.item else result
-    
+
     def __getattribute__(self, __name: str) -> Any:
         try:
             return super().__getattribute__(__name)
diff --git a/znflow/exceptions.py b/znflow/exceptions.py
index e486076..227fc47 100644
--- a/znflow/exceptions.py
+++ b/znflow/exceptions.py
@@ -1,4 +1,5 @@
 """ZnFlow exceptions."""
 
+
 class ConnectionAttributeError(AttributeError):
     """Raised when a connection attribute is not found."""