Instructions

In knitting, the bulkier the yarn, the smaller the number of stitches that can be fit into a 4-inch piece of knitting.

Improve the function yarn_size by making the conditions used in branching simpler and by replacing "magic numbers" by constants, such as BULKY_MAX for the maximum number of stitches for bulky yarn.

Do not change the name of the function.

Note:

Hint:

  • Notice the restriction on values of stitches given in the docstring.

A baker will offer a "baker's dozen" by giving thirteen items for the cost of twelve. To calculate the total cost, charge for as many "baker's dozens" as possible. The rest of the items will cost either the cost of a dozen, if there are twelve left, or the number of items times the cost of a single item.

You should assume that the cost of eleven items is eleven times the cost of a single item, even if that is more expensive than buying twelve.

Write a function for the constants, docstring, header, and comments that have been provided.

Note:

Hints:

  • undefined

Modify the function you wrote to make it more general by adding parameters for the cost of a dozen and cost of a single item, in that order. Keep items as the first parameter. Don't forget to modify the docstring.

Note:

Hints:

  • undefined

Postal codes in the United Kingdom come in a variety of forms, given below. In each form, a 9 is used to represent any digit and a letter A is used to represent any letter. We will not differentiate between upper-case and lower-case letters.

A9 9AA
A9A 9AA
A99 9AA
AA9 9AA
AA9A 9AA
AA99 9AA

Start by writing a helper function code_ending which determines if the last four characters are of the form " 9AA".

Notice from the docstring that you can assume that input to the main function consists of only letters, digits, and spaces.

Also notice from the order of conditions being checked that you can assume that the input to the helper function has length 6, 7, or 8.

Your function should accept both lower-case and upper-case letters.

This question is concerned with the helper function only. You will be completing the rest of uk_code in the next two questions.

Note:

Hint:

  • Make sure that the name of your helper function is code_ending and that it has one parameter.

Now add a helper function code_eight that determines if a string of length 8 is of the right form to be a postal code.

Pay close attention to what preconditions are true of the input to the helper function: this will make your job much easier.

Note:

Hints:

  • undefined

Now complete the function uk_code using your helper functions.

Note:

Hints:

  • undefined
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