Wanaryytel master

README.rst

@@ -68,6 +68,17 @@ Added indicies are filled with None by default.
 >>> l
 [None, None, 'C', None, None]
 
+However, you can specify initial values to the list just like in defaultdict.
+
+>>> l = defaultlist(None, [123, 'abc', 'qwerty'])
+>>> l
+[123, 'abc', 'qwerty']
+>>> l[8] = "C"
+>>> l
+[123, 'abc', 'qwerty', None, None, None, None, None, 'C']
+>>> l[4]
+>>>
+
 Slices and negative indicies are supported likewise
 
 >>> l[1:4]

defaultlist.py

@@ -20,6 +20,16 @@
 >>> l[-3]
 'C'
 
+However, you can specify initial values to the list just like in defaultdict.
+
+>>> l = defaultlist(None, [123, 'abc', 'qwerty'])
+>>> l
+[123, 'abc', 'qwerty']
+>>> l[8] = "C"
+>>> l
+[123, 'abc', 'qwerty', None, None, None, None, None, 'C']
+>>> l[4]
+
 Simple factory functions can be created via `lambda`.
 
 >>> l = defaultlist(lambda: 'empty')
@@ -73,8 +83,14 @@ class defaultlist(list):
         factory: Function called for every missing index.
     """
 
-    def __init__(self, factory=None):
+    def __init__(self, factory=None, data=None):
         self.__factory = factory or defaultlist.__nonefactory
+        if data:
+            list.__init__(self, data)
+        else:
+            list.__init__(
+                self,
+            )
 
     @staticmethod
     def __nonefactory():

tests/test_defaultlist.py

@@ -189,3 +189,20 @@ def test_len():
     assert len(dfl) == 3
     assert dfl[4] is None
     assert len(dfl) == 5
+
+
+def test_initial_data():
+    """Initial Data"""
+    dfl = defaultlist(None, ["a", "b"])
+    assert len(dfl) == 2
+    dfl[15] = 42
+    assert len(dfl) == 16
+    assert dfl[1] == "b"
+
+    dfl2 = defaultlist(None, [None, None, 1, None])
+    assert len(dfl2) == 4
+    dfl2[1] = "q"
+    assert dfl2[1:3] == ["q", 1]
+    assert dfl2[-1] is None
+    dfl2[-1] = "last?"
+    assert dfl2[-1] == "last?"