Adding mean animals command line script.

diff --git a/python/sw_engineering/mean_sighted.py b/python/sw_engineering/mean_sighted.py
new file mode 100755 (executable)
index 0000000..51aea49
--- /dev/null
+++ b/python/sw_engineering/mean_sighted.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+
+# The line above tells the shell to run this script with Python.
+import sys
+
+from meananimals import mean_animals
+
+# sys.argv contains the arguments the user entered at the command line when
+# calling this script. See more at http://docs.python.org/2/library/sys.html.
+# Another great way of putting together command line interfaces for scripts
+# is the argparse module: http://docs.python.org/2/library/argparse.html
+
+# Try running this script by typing "./mean_sighted.py big_animals.txt Elk"
+# at the command line.
+
+if len(sys.argv) != 3:
+    print 'Usage: mean_sighted.py <filename> <species>'
+else:
+    filename = sys.argv[1]
+    species = sys.argv[2]
+    print mean_animals(filename, species)