create simple binary search (#1430)

* create simnple binary search

#A binary search implementation to test if a number is in a list of elements

* Add .py, format with psf/black, and add doctests

searches/simple-binary-search.py

@@ -0,0 +1,26 @@
+# A binary search implementation to test if a number is in a list of elements
+
+
+def binary_search(a_list, item):
+    """
+    >>> test_list = [0, 1, 2, 8, 13, 17, 19, 32, 42]
+    >>> print(binary_search(test_list, 3))
+    False
+    >>> print(binary_search(test_list, 13))
+    True
+    """
+    if len(a_list) == 0:
+        return False
+    midpoint = len(a_list) // 2
+    if a_list[midpoint] == item:
+        return True
+    if item < a_list[midpoint]:
+        return binary_search(a_list[:midpoint], item)
+    else:
+        return binary_search(a_list[midpoint + 1 :], item)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()