From eef3a2c79af2406f5ba444e456364f0fb53be289 Mon Sep 17 00:00:00 2001
From: Prodesire <prodesire@yeah.net>
Date: Tue, 21 Nov 2017 13:10:44 +0800
Subject: [PATCH] add uniq to list

---
 pydu/list.py       | 17 +++++++++++++++++
 tests/test_list.py |  5 +++++
 2 files changed, 22 insertions(+)
 create mode 100644 pydu/list.py
 create mode 100644 tests/test_list.py

diff --git a/pydu/list.py b/pydu/list.py
new file mode 100644
index 0000000..503bb3a
--- /dev/null
+++ b/pydu/list.py
@@ -0,0 +1,17 @@
+def uniq(seq, key=None):
+    """
+    Removes duplicate elements from a list while preserving the order of the rest.
+
+    The value of the optional `key` parameter should be a function that
+    takes a single argument and returns a key to test the uniqueness.
+    """
+    key = key or (lambda x: x)
+    seen = set()
+    uniq_list = []
+    for value in seq:
+        uniq_value = key(value)
+        if uniq_value in seen:
+            continue
+        seen.add(uniq_value)
+        uniq_list.append(value)
+    return uniq_list
diff --git a/tests/test_list.py b/tests/test_list.py
new file mode 100644
index 0000000..dafba83
--- /dev/null
+++ b/tests/test_list.py
@@ -0,0 +1,5 @@
+from pydu.list import uniq
+
+
+def test_uniq():
+    assert uniq([1, 4, 0, 2, 0, 3]) == [1, 4, 0, 2, 3]