Update recipe-576917.py

kgashok · web-flow · commit 1c8ea280ac1b · 2017-11-15T07:10:44.000+05:30
included a lambda version (&lt;2.7?) and added a &gt;3.5x version as well.
diff --git a/recipes/Python/576917_Functional_selection_sort/recipe-576917.py b/recipes/Python/576917_Functional_selection_sort/recipe-576917.py
@@ -16,8 +16,33 @@
 print test_list
 print selection_sort(test_list)
 
+
 # Recursive version
 def select_sort_r(L):
     if not L: return [] # terminal case 
     v, idx = min((v, i) for i, v in enumerate(L)) # select the smallest
     return [v] + select_sort_r(L[:idx] + L[idx+1:]) # recursively call on the remainder
+
+
+# Lambda version 
+# Python > 2.7.10 and above
+select_sort_l = (
+    lambda L: [] if not L else (
+        lambda idx, v: [v] + select_sort_l(L[:idx] + L[idx + 1:]))(
+            *min(enumerate(L), key=lambda t: t[1])
+    )
+)
+
+# OP's version from the comments, works probably for Python < 2.7.10 
+selsort2 = (lambda l: [] if not l else
+            (lambda (idx, v): [v] + selsort2(l[:idx] + l[idx + 1:]))
+            (min(enumerate(l), key=lambda(i, x): x)))
+
+
+# OP's original test_list gets mutated by the functional version
+test_list = [5, 1, 7, 0, -3, -10, 10, -6, 1, 0, 2, 4, -2, 6, 5, 8, 2]
+expected  = [-10, -6, -3, -2, 0, 0, 1, 1, 2, 2, 4, 5, 5, 6, 7, 8, 10]
+
+assert select_sort_r(test_list) == expected 
+assert select_sort_l(test_list) == expected 
+# assert selsort2(test_list) == expected 
