Python’s Magic Methods: Two’s Complement Binary Numbers ISTA 350 Hw4,

Introduction. This homework is intended to acquaint you with Python’s operator overloading functionality (magic methods) and the basics of binary integer arithmetic as it is done inside in computers. You have already been using operator overloading without knowing what it’s called. For example, the plus sign is commonly and in Python used to add numbers. But it is also used for string concatenation. That is an example of operator overloading. Instructions. Create a module named hw4.py. Below is the spec for ten methods. Implement them and upload your module to the D2L dropbox. Testing. Download hw4_test.py and put it in the same folder as your hw4.py module. Run it from the command line to see your current correctness score. Each of the 10 methods s worth 10% of your correctness score. You can examine the test module in a text editor to understand better what your code should do. The test module is part of the spec. The test file we will use to grade your program will be different and may uncover failings in your work not evident upon testing with the provided file. Add any necessary tests to make sure your code works in all cases.
Documentation. Your module must contain a header docstring containing your name, your section leader’s name, the date, ISTA 350 Hw4, and a brief summary of the module. Each method/function must contain a docstring. Each docstring should include a description of the function’s purpose, the name, type, and purpose of each parameter, and the type and meaning of the function’s return value. Grading. Your module will be graded on correctness, documentation, and coding style. Code should be clear and concise. You will only lose style points if your code is a real mess. Include inline comments to explain tricky lines and summarize sections of code (not necessary on this assignment). Collaboration. Collaboration is allowed. You are responsible for your learning. Depending too much on others will hurt you on the tests. “Helping” others too much harms them in reality. Cite any sources/collaborators in your header docstring. Leaving this out is dishonest. Resources. https://docs.python.org/3.4/tutorial/index.html https://docs.python.org/3.4/tutorial/classes.html Tkinter: http://effbot.org/tkinterbook/tkinter-events-and-bindings.htm http://www.tutorialspoint.com/python/python_gui_programming.htm https://wiki.python.org/moin/TkInter class Binary: If you use any method you have defined in another method definition, use the overloaded operator, if there is one. For instance, you will lose points if we see anything like bin1.__add__(bin2). This should be bin1 + bin2. init: init has one string parameter with a default argument of '0'. This string can be the empty string (treat the same as '0'). Otherwise, it should consist only of 0’s and 1’s and should be 16 or less characters long. If the argument does not meet these requirements, raise a RuntimeError. Each Binary object has one instance variable, a list called num_list. num_list has integers 0 or 1 in the same order as the corresponding characters in the argument. If the string is less than 16 characters long, num_list should be padded by repeating the leftmost digit until the list has 16 elements. This is to be done by calling the next method. pad: Pad num_list by repeating the leftmost digit until the list has 16 elements. repr: Return a 16-character string representing the fixed-width binary number, such as: '00000000000000000'. add: Takes a Binary object as an argument. Return a new Binary instance that represents the sum of self and the argument. If the sum requires more than 16 digits, raise a RuntimeError. neg: Return a new Binary instance that equals -self. sub: Takes a Binary object as an argument. Return a new Binary instance that represents self – the argument. int: Return the decimal value of the Binary object. This method should never raise a RuntimeError due to overflow. Do not use int on Binary objects in any other method. You may use it to convert strings to integers, but not on Binary objects. eq: Takes a Binary object as an argument. Return True if self == the argument, False otherwise. lt: Takes a Binary object as an argument. Return True if self < the argument, False otherwise. This method should never raise a RuntimeError due to overflow. abs: Return a new instance that is the absolute value of self.