Code and structure for week06 docs exercises

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

@@ -0,0 +1,62 @@
+"""Computation of weighted average of squares."""
+
+
+def average_of_squares(list_of_numbers, list_of_weights=None):
+    """ Return the weighted average of a list of values.
+
+    By default, all values are equally weighted, but this can be changed
+    by the list_of_weights argument.
+
+    Example:
+    --------
+    >>> average_of_squares([1, 2, 4])
+    7.0
+    >>> average_of_squares([2, 4], [1, 0.5])
+    6.0
+    >>> average_of_squares([1, 2, 4], [1, 0.5])
+    Traceback (most recent call last):
+    AssertionError: weights and numbers must have same length
+
+    """
+    if list_of_weights is not None:
+        assert len(list_of_weights) == len(list_of_numbers), \
+            "weights and numbers must have same length"
+        effective_weights = list_of_weights
+    else:
+        effective_weights = [1] * len(list_of_numbers)
+    squares = [
+        weight * number * number
+        for number, weight
+        in zip(list_of_numbers, effective_weights)
+    ]
+    return sum(squares)
+
+
+def convert_numbers(list_of_strings):
+    """Convert a list of strings into numbers, ignoring whitespace.
+
+    Example:
+    --------
+    >>> convert_numbers(["4", " 8 ", "15 16", " 23    42 "])
+    [4, 8, 15, 16]
+
+    """
+    all_numbers = []
+    for s in list_of_strings:
+        # Take each string in the list, split it into substrings separated by
+        # whitespace, and collect them into a single list...
+        all_numbers.extend([token.strip() for token in s.split()])
+    # ...then convert each substring into a number
+    return [float(number_string) for number_string in all_numbers]
+
+
+if __name__ == "__main__":
+    numbers_strings = ["1","2","4"]
+    weight_strings = ["1","1","1"]        
+
+    numbers = convert_numbers(numbers_strings)
+    weights = convert_numbers(weight_strings)
+
+    result = average_of_squares(numbers, weights)
+
+    print(result)