add method unnest

README.md

@@ -616,7 +616,7 @@ Partially supported
 - [x] 0.1.2 uniqBy
 - [x] 0.1.2 uniqWith
 - [ ] unless
-- [ ] unnest
+- [x] unnest
 - [ ] until
 - [ ] unwind
 - [ ] update

ramda/__init__.py

@@ -111,6 +111,7 @@
 from .uniq import uniq
 from .uniqBy import uniqBy
 from .uniqWith import uniqWith
+from .unnest import unnest
 from .useWith import useWith
 from .values import values
 from .valuesIn import valuesIn

ramda/unnest.py

@@ -0,0 +1,4 @@
+from .chain import chain
+from .private._identity import _identity
+
+unnest = chain(_identity)

test/test_unnest.py

@@ -0,0 +1,38 @@
+
+import unittest
+
+import ramda as R
+
+from .helpers.Maybe import Just, Nothing
+
+"""
+https://github.com/ramda/ramda/blob/master/test/unnest.js
+"""
+
+
+class TestUnnest(unittest.TestCase):
+  def test_only_flattens_one_layer_deep_of_a_nested_list(self):
+    nest = [1, [2], [3, [4, 5], 6, [[[7], 8]]], 9, 10]
+    self.assertEqual([1, 2, 3, [4, 5], 6, [[[7], 8]], 9, 10], R.unnest(nest))
+    nest = [[[[3]], 2, 1], 0, [[-1, -2], -3]]
+    self.assertEqual([[[3]], 2, 1, 0, [-1, -2], -3], R.unnest(nest))
+    self.assertEqual([1, 2, 3, 4, 5], R.unnest([1, 2, 3, 4, 5]))
+
+  def test_is_not_destructive(self):
+    nest = [1, [2], [3, [4, 5], 6, [[[7], 8]]], 9, 10]
+    self.assertNotEqual(nest, R.unnest(nest))
+
+  def test_flattens_an_array_of_empty_arrays(self):
+    self.assertEqual([], R.unnest([[], [], []]))
+    self.assertEqual([], R.unnest([]))
+
+  def test_is_equivalent_to_R_chain_R_identity(self):
+    self.assertTrue(R.unnest(Nothing()).isNothing)
+    self.assertTrue(R.unnest(Just(Nothing())).isNothing)
+    self.assertTrue(R.equals(Just(Nothing()), R.unnest(Just(Just(Nothing())))))
+    self.assertTrue(R.equals(Just(42), R.unnest(Just(Just(42)))))
+    self.assertTrue(R.equals(Just(Just(42)), R.unnest(Just(Just(Just(42))))))
+
+
+if __name__ == '__main__':
+  unittest.main()