add solution week 271 task 2 in python

1 files changed, 22 insertions, 0 deletions

diff --git a/challenge-271/steven-wilson/python/ch-2.py b/challenge-271/steven-wilson/python/ch-2.py
new file mode 100644
index 0000000000..23bd2b8fde
--- /dev/null
+++ b/challenge-271/steven-wilson/python/ch-2.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+
+from operator import itemgetter
+
+
+def sort_by_1_bits(*integers):
+    ''' Given an array of integers, sort the integers in ascending order by the
+    number of 1 bits in their binary representation. In case more than one
+    integers have the same number of 1 bits then sort them in ascending order.
+    >>> sort_by_1_bits(0, 1, 2, 3, 4, 5, 6, 7, 8)
+    (0, 1, 2, 4, 8, 3, 5, 6, 7)
+    >>> sort_by_1_bits(1024, 512, 256, 128, 64)
+    (64, 128, 256, 512, 1024)
+    '''
+    number_of_1_bits = ((str(bin(i)).count('1'), i) for i in sorted(integers))
+    return tuple([i[1] for i in sorted(number_of_1_bits, key=itemgetter(0))])
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod(verbose=True)