fix bug if list empty or first item is None

Author: Clement-O

pyduplicate/data/utils.py

@@ -15,6 +15,8 @@ def __init__(self, lst: list) -> None:
         self.indexes = {}
         self.lst = lst
         self.item_type = list
+        if not self.lst:
+            raise IndexError(f'You must not supply an empty list')
 
     def create_list(self, key: str) -> None:
         """
@@ -26,25 +28,27 @@ def create_list(self, key: str) -> None:
 
     def get_type(self) -> None:
         """
-        Get the type of the first item
+        Get the type of the first item which is not None
         """
-        item = self.lst[0]
-        if isinstance(item, (int, float)):
-            self.item_type = (int, float)
-        elif isinstance(item, str):
-            self.item_type = str
-        elif isinstance(item, dict):
-            self.item_type = dict
-        elif isinstance(item, tuple):
-            self.item_type = tuple
+        for item in self.lst:
+            if item:
+                if isinstance(item, (int, float)):
+                    self.item_type = (int, float)
+                elif isinstance(item, str):
+                    self.item_type = str
+                elif isinstance(item, dict):
+                    self.item_type = dict
+                elif isinstance(item, tuple):
+                    self.item_type = tuple
+                break
 
     def validate_items(self) -> None:
         """
         Check if all items are of the same type
 
         :raise TypeError: If items are NOT of the same type
         """
-        if not all(isinstance(x, self.item_type) for x in self.lst):
+        if not all(isinstance(x, self.item_type) for x in self.lst if x):
             raise TypeError(f'An item has a different type than the others')
 
     def create_update_feedback(self, index: int, value: any,

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name="python-duplicate",
-    version="1.0.2",
+    version="1.0.4",
     url="https://github.com/Clement-O/python-duplicate",
     license="MIT",
     author="Clément Omont--Agnes",

test/data/test_utils.py

@@ -8,6 +8,23 @@
 
 class TestUtils(unittest.TestCase):
 
+    def test_init_error(self):
+        with self.assertRaises(IndexError):
+            Utils([])
+
+    def test_get_type(self):
+        value = [{}, {'id': 1}]
+        utils = Utils(value)
+        utils.create_list('id')
+        utils.get_type()
+        self.assertEqual(utils.item_type, (int, float))
+
+        value = [{}, {}]
+        utils = Utils(value)
+        utils.create_list('id')
+        utils.get_type()
+        self.assertEqual(utils.item_type, list)  # default type
+
     def test_validate_items(self):
         # mixed list (and dict without key)
         for index, value in enumerate(test_const.LIST_ERROR):