Introduction to Computing Using Python Group practice in

Introduction to Computing Using Python Group practice in problem design and problem solving § In this lesson, you will work together in small groups to § design a programming problem such as might be given on a test (15 -20 minutes) § submit your problem to a Moodle forum § solve one or two of the problems your class designs (15 -20 minutes per problem) § (one group should) present a solution (~10 minutes) § (each person should) rate the programming problem for difficulty and clarity

Introduction to Computing Using Python Design a programming problem § Work together in small groups (for example, of three) to design a good programming problem (15 -20 minutes) § Your problem might be similar to Question 13 on Midterm 2. It would have these elements § specify that the reader write a function that takes a file name as a parameter § describe the content of the file (e. g. , text or numbers or a combination; including punctuation or not. . . ) § specify a property of the input file that the function should compute § specify whether to write the result to an output file or to return the result in a dictionary § give an example of correct input and output

Introduction to Computing Using Python The content of the input file § The input file could have any content made up of characters (text) § It might be line-by-line content, such as § A name followed by height and weight § The lines of a poem or lyric § A year followed by the 10 most popular baby names for that year § Or it might be a block of text consisting of words separated by white space (white space includes spaces, tabs and end line characters) § Or it might be a sequence of numbers (integers or floats) § Use your imagination!

Introduction to Computing Using Python Tell the problem solver to analyze. . . § Some property or relationship of the elements on each line § A person's name and the person's zodiac sign § Length of the line (in words or characters) or the number of short words on a line, or the number of big numbers on a line. . . OR § Some property of the words in the file (without regard to the line structure) § Length of words, or frequency of words § Distribution of upper and lower case characters § Words beginning (or ending) in a certain way, or containing certain characters § Hint: what is to be analyzed will determine whether the solution should read the file all at once (using the read() method) or line by line (using a for loop or readline() or readlines() method)

Introduction to Computing Using Python How hard should your problem be? § Give your problem a reasonable level of difficulty § A problem with a 3 line solution is probably too easy § A problem with a 30 line solution is probably too hard § Try to make the problem solver do some thinking. . . (minutes of thinking, not hours) § Make the solution use some combination (not necessarily all!) of things we have learned, such as § data types (strings, lists, numbers) § built-in operators and functions (in, not, len(), range() ) § methods (append(), count() ) § flow control structures such as the for loop and if statement

Introduction to Computing Using Python How to describe the problem § Make your description of the problem as clear and simple as possible § Be specific about the parameters (input) to the function and the output of the function § Give helpful hints and guidance § Include a good example of input and output § The example should be short enough so that the problem solver can follow your instructions for analyzing the input to arrive at the output § The example should illustrate how to handle any different cases of input and clarify possible pitfalls

Introduction to Computing Using Python Solve the problem (15 -20 minutes) § Work together in your small group to solve the problem § Read the problem carefully. Discuss it and make sure that you agree on what it is the problem asks you to do. § Work the example. Make sure that you arrive at the correct output. § Share ideas how to approach the problem § What value(s) do you need to keep track of? What variables do you need to store these values? § Are there repeated operations? What control structure (loop) governs the repetition? § Are there conditional operations? What are the conditions (Boolean expressions) for doing or not doing the operation? § Make sure your code works on the example given § Create your own test case and try your code on it

Introduction to Computing Using Python Present your solution (~10 minutes) § At the end of the allotted time, one group should present their solution § In your own words, present your understanding of what the problem asks you to do § Report the state of your solution § What is the core problem and how does your code solve it? § Your solution may not be complete or fully correct. (That is a common state of affairs. ) Convey the state of the solution, including any problems that you are aware of § Does your code run or does it terminate with an error message? § Does your solution give the same output as the example? § If the output is not correct, where do you think the problem might lie?

Introduction to Computing Using Python Rate the problem § Each person should rate the problem (for example, by a show of hands) § On a scale of 1 to 5, how clear is the problem description? § On a scale of 1 to 5, how difficult is the problem? § Is the problem a reasonable test of what we have learned so far this semester?