Numbers to be averaged now taken as command-line argument

week06/average-squares-example/average_squares/squares.py

@@ -1,5 +1,6 @@
 """Computation of weighted average of squares."""
 
+from argparse import ArgumentParser
 
 def average_of_squares(list_of_numbers, list_of_weights=None):
     """ Return the weighted average of a list of values.
@@ -12,7 +13,7 @@ def average_of_squares(list_of_numbers, list_of_weights=None):
     >>> average_of_squares([1, 2, 4])
     7.0
     >>> average_of_squares([2, 4], [1, 0.5])
-    6.0
+    8.0
     >>> average_of_squares([1, 2, 4], [1, 0.5])
     Traceback (most recent call last):
     AssertionError: weights and numbers must have same length
@@ -29,7 +30,7 @@ def average_of_squares(list_of_numbers, list_of_weights=None):
         for number, weight
         in zip(list_of_numbers, effective_weights)
     ]
-    return sum(squares)
+    return sum(squares)/sum(effective_weights)
 
 
 def convert_numbers(list_of_strings):
@@ -38,7 +39,7 @@ def convert_numbers(list_of_strings):
     Example:
     --------
     >>> convert_numbers(["4", " 8 ", "15 16", " 23    42 "])
-    [4, 8, 15, 16]
+    [4.0, 8.0, 15.0, 16.0, 23.0, 42.0]
 
     """
     all_numbers = []
@@ -51,12 +52,12 @@ def convert_numbers(list_of_strings):
 
 
 if __name__ == "__main__":
-    numbers_strings = ["1","2","4"]
-    weight_strings = ["1","1","1"]        
-
-    numbers = convert_numbers(numbers_strings)
-    weights = convert_numbers(weight_strings)
+    parser = ArgumentParser(description="Average of squares")
+    parser.add_argument('numbers', action='append', nargs='+')
+    arguments= parser.parse_args()
+
+    numbers = convert_numbers(arguments.numbers[0])
 
-    result = average_of_squares(numbers, weights)
+    result = average_of_squares(numbers)
 
     print(result)