This must be in Python!!! Read everything carefully!!!

Exceptions:

Reminder: you can run individual inputs, such as get(['a','b','c'],0) by loading your file into interactive mode with the i flag. You should be using this technique on projects as well. demo$ python3 i gmason_2B5_L10.py >>> get (['a', 'b', 'c'], 0 ) 'a'

Exceptions provide a new form of control flow that also addresses code that crashes. We are able to identify questionable code by placing it in a try block, and then we can selectively catch and respond to different kinds of errors based on the type of issue that occurs.

You might also write code in a style of "ask for forgiveness" rather than "look before you leap" by just attempting the code (in a try block) that you know will easily work on good input, and then just write the response to failure afterwards.

In python, exception handling is particularly cheap (efficient); it's considered normal to use exception handling in many ways throughout our python code.

Remember, if you didn't use try/except blocks on a question when required, you won't get credit for it!

What can I use?

There are no restrictions on what functions to use on this lab use this time to learn how to raise exceptions, how to catch exceptions, and how to use exception handling to deal with special cases.

get(xs, index, response=None): Consider a list of values, xs. Find and return the value at location index. If index is invalid for xs, return response instead. Remember that .get() for dictionaries works gracefully for non-existing keys. Here we are implementing a get() function for list type.

Parameters:

o xs :: list of values of any length.

o index :: an integer, specifying which value in the list to return.

o response :: a python value, to be returned when index is invalid for the list.

Return value: a value from xs at index or the pre-set response.

Requirement: you must use try-except blocks in your solution!

Examples:

o get(['a','b','c'],0) 'a'

o get(['a','b','c'],3) None o get(['a','b','c'],4,"oops") 'oops'

classify(input_string): It takes as input a string with a mixed group of integers and words separated by spaces. It returns a tuple of two lists: a list of integers and a list of non-empty words. Use exceptions to distribute words and integers to their respective lists. Note: do NOT include empty string in the return list; any string that does not include an integer only (e.g. '$10' or '3.00') should be classified as words. Hint: check what happens when you call int() on strings like '3.00'.

Parameter: input_string :: string with a group of integers and words separated by spaces.

Return value: a tuple of a list of integers(int) and a list of words(string).

Requirement: you must use try-except blocks in your solution!

Examples:

o classify("I have 35 apples") ([35], ['I', 'have', 'apples'])

o classify("Today is Sunday") ([],['Today', 'is', 'Sunday'])

o classify("That will be $10 please") ([],['That','will','be','$10','please'])

shelve(inventory, product_list): Given a dictionary, inventory, and a list of tuples product_list, we need to update the inventory with products listed in product_list: if a product is already in store, update the amount; if the product is not in store, add a new entry in inventory for it. We might also call this function to update inventory when the stock amount is decreased. But if the amount of any product is below zero, we must raise a ValueError with the "negative amount for product" message.

Parameters:

o inventory :: a dictionary with product name (string) keys and product amount (int) values.

o product_list :: a list of tuples, each tuple has two members: a string as the product name and an integer as the amount.

Returns: None. You should make update to inventory in-place.

Raises: ValueError when the amount of a product is below zero.

Examples:

o >>> d = {"apple":50, "pear":30, "orange":25} >>> ps = [("apple",20),("pear",-10),("grape",18)] >>> shelve(d,ps) >>> d {'pear': 20, 'grape': 18, 'orange': 25, 'apple': 70} >>> shelve(d,[("apple",-1000)]) Traceback (most recent call last): ValueError: negative amount for apple