MonoPatchStackFromFile now contains file accessor as an object

extensions/chaeo/accessors.py

+from pathlib import Path
+
 import numpy as np
+
 from model_server.accessors import generate_file_accessor, InMemoryDataAccessor
 
 class MonoPatchStack(InMemoryDataAccessor):
@@ -48,11 +51,17 @@ class MonoPatchStack(InMemoryDataAccessor):
 
 class MonoPatchStackFromFile(MonoPatchStack):
     def __init__(self, fpath):
-        super().__init__(generate_file_accessor(fpath).data[:, :, 0, :])
+        if not Path(fpath).exists():
+            raise FileNotFoundError(f'Could not find {fpath}')
+        self.file_acc = generate_file_accessor(fpath)
+        super().__init__(self.file_acc.data[:, :, 0, :])
 
 
 class Error(Exception):
     pass
 
 class InvalidDataForPatchStackError(Error):
-    pass
\ No newline at end of file
+    pass
+
+class FileNotFoundError(Error):
+    pass

extensions/chaeo/tests/test_accessors.py

@@ -2,7 +2,8 @@ import unittest
 
 import numpy as np
 
-from extensions.chaeo.accessors import MonoPatchStack
+from conf.testing import monozstackmask
+from extensions.chaeo.accessors import MonoPatchStack, MonoPatchStackFromFile
 
 
 
@@ -26,4 +27,19 @@ class TestCziImageFileAccess(unittest.TestCase):
         acc = MonoPatchStack([np.random.rand(h, w) for _ in range(0, 4)])
         self.assertEqual(acc.count, n)
         self.assertEqual(acc.hw, (h, w))
-        self.assertEqual(acc.make_tczyx().shape, (n, 1, 1, h, w))
\ No newline at end of file
+        self.assertEqual(acc.make_tczyx().shape, (n, 1, 1, h, w))
+
+    def test_make_patch_stack_from_file(self):
+        h = monozstackmask['h']
+        w = monozstackmask['w']
+        c = monozstackmask['c']
+        n = monozstackmask['z']
+        acc = MonoPatchStackFromFile(monozstackmask['path'])
+        self.assertEqual(acc.hw, (h, w))
+        self.assertEqual(acc.count, n)
+        self.assertEqual(acc.make_tczyx().shape, (n, c, 1, h, w))
+
+    def test_raises_filenotfound(self):
+        from extensions.chaeo.accessors import FileNotFoundError
+        with self.assertRaises(FileNotFoundError):
+            acc = MonoPatchStackFromFile('c:/fake/file/name.tif')
\ No newline at end of file