Source code for simplestatistics.statistics.product

[docs]def product(x, y): """ This function calculates the product of two vectors or lists of numerical objects, like so: .. math:: [x_1, x_2, x_3, x_4] \\times [y_1, y_2, y_3, y_4] = [x_1y_1, x_2y_2, x_3y_3, x_4y_4] Args: x: An int or a float, or a list or tuple of numerical objects. y: An int or a float, or a list or tuple of numerical objects. If a list or tuple, must have the same length as x. Returns: A list of numerical objects of the same length as x and y. Examples: >>> product([1, 2, 3], [1, 2, 3]) [1, 4, 9] >>> product((2, 3), (3, -1)) [6, -3] >>> product([1.25, 2.75], [2.5, 3.40]) [3.125, 9.35] >>> product(2, [1, 2, 3]) [2, 4, 6] >>> product([-3, -2, -1], 3) [-9, -6, -3] >>> product(5.5, 6.4) 35.2 >>> product('a', [2, 4]) Traceback (most recent call last): ... TypeError: product() expects ints, floats, lists, or tuples of numbers. >>> product([1, 2], [3, 4, 5]) Traceback (most recent call last): ... ValueError: The two lists or tuples have to have equal lengths """ # product can work with two list, two tuples, two ints, # or an int and one of the others if type(x) not in [int, float, list, tuple] or type(y) not in [int, float, list, tuple]: raise TypeError('product() expects ints, floats, lists, or tuples of numbers.') # if you provide lists or tuples, they have to have the same length # for now if type(x) in [list, tuple] and type(y) in [list, tuple] and len(x) != len(y): raise ValueError('The two lists or tuples have to have equal lengths') product_vector = [] # I'm not very happy with this if-else heavy implementation # but can't think of how to do this in a smarter more dynamic way # if both are ints, return their product if type(x) in [int, float] and type(y) in [int, float]: return(x * y) # if x is int, y must be a float, list, or tuple elif type(x) in [int, float]: for ii in range(len(y)): product_vector.append(x * y[ii]) # if y is int, x must be a float, list, or tuple elif type(y) in [int, float]: for ii in range(len(x)): product_vector.append(x[ii] * y) # else, both are lists or tuples else: for ii in range(len(x)): product_vector.append(x[ii] * y[ii]) return(product_vector)