WEBVTT 00:00:00.000 --> 00:00:02.880 align:middle line:90% [SQUEAKING] 00:00:02.880 --> 00:00:04.320 align:middle line:90% [RUSTLING] 00:00:04.320 --> 00:00:07.200 align:middle line:90% [CLICKING] 00:00:07.200 --> 00:00:09.927 align:middle line:90% 00:00:09.927 --> 00:00:11.510 align:middle line:84% MICHAEL SCOTT ASATO CUTHBERT: Hello, I 00:00:11.510 --> 00:00:16.200 align:middle line:84% want to give a sense of how some problem sets are going to work 00:00:16.200 --> 00:00:17.760 align:middle line:90% or the majority of the time. 00:00:17.760 --> 00:00:22.550 align:middle line:84% Generally speaking, you'll be given some instructions on what 00:00:22.550 --> 00:00:25.580 align:middle line:84% to do like, write a routine that takes a string representing 00:00:25.580 --> 00:00:28.530 align:middle line:84% an enharmonic with minus sign for flats-- 00:00:28.530 --> 00:00:31.640 align:middle line:84% we'll talk about that in a bit --and number sign for sharps 00:00:31.640 --> 00:00:35.540 align:middle line:84% and return a new string that is an enharmonic-- 00:00:35.540 --> 00:00:38.120 align:middle line:84% you're not allowed to change it, but I can here. 00:00:38.120 --> 00:00:42.090 align:middle line:84% That is an enharmonic of the pitch. 00:00:42.090 --> 00:00:44.130 align:middle line:84% You will be given valid input only. 00:00:44.130 --> 00:00:48.770 align:middle line:84% I will always tell if you have to check for invalid input. 00:00:48.770 --> 00:00:50.910 align:middle line:84% If there's more than one valid enharmonic, 00:00:50.910 --> 00:00:53.670 align:middle line:84% you can give any enharmonic up to double flats or sharps. 00:00:53.670 --> 00:00:59.330 align:middle line:84% Then below, you're going to be given the name of the routine 00:00:59.330 --> 00:01:01.490 align:middle line:84% that you're going to need to write, along 00:01:01.490 --> 00:01:07.280 align:middle line:84% with usually the name of a variable that you should use 00:01:07.280 --> 00:01:10.190 align:middle line:84% and the type, if you haven't looked at Python typing, 00:01:10.190 --> 00:01:14.855 align:middle line:84% this can be really exciting, and what's output. 00:01:14.855 --> 00:01:19.170 align:middle line:84% At this point, you need to define the routine. 00:01:19.170 --> 00:01:22.640 align:middle line:84% Quite often, you can take some of the language 00:01:22.640 --> 00:01:25.160 align:middle line:84% from above but make it in your own words 00:01:25.160 --> 00:01:28.580 align:middle line:90% and to see what happens. 00:01:28.580 --> 00:01:32.930 align:middle line:84% But put it in the active voice, takes in a string 00:01:32.930 --> 00:01:35.750 align:middle line:90% representing a pitch-- 00:01:35.750 --> 00:01:38.690 align:middle line:84% sorry, I should say representing a pitch earlier 00:01:38.690 --> 00:01:48.130 align:middle line:84% --and returns a valid enharmonic for it. 00:01:48.130 --> 00:01:51.260 align:middle line:90% 00:01:51.260 --> 00:01:55.070 align:middle line:84% If there's specific things that constrain 00:01:55.070 --> 00:01:58.440 align:middle line:84% what the valid input might be, I'll tend to write it here, 00:01:58.440 --> 00:02:00.980 align:middle line:90% or you should be writing it in. 00:02:00.980 --> 00:02:05.790 align:middle line:84% We write for humans to read, not just for computers to process. 00:02:05.790 --> 00:02:07.730 align:middle line:84% So it's always going to be important 00:02:07.730 --> 00:02:13.940 align:middle line:84% that your code be documented and that your variable names be 00:02:13.940 --> 00:02:16.620 align:middle line:84% things that humans can understand. 00:02:16.620 --> 00:02:21.660 align:middle line:84% OK, so then you can go ahead and write your code. 00:02:21.660 --> 00:02:24.720 align:middle line:84% And if you're a not-so-great programmer, 00:02:24.720 --> 00:02:32.480 align:middle line:84% maybe you'll start with if enharmonis_in is E flat-- 00:02:32.480 --> 00:02:38.300 align:middle line:84% we're going to use minus signs for flat --return D sharp, 00:02:38.300 --> 00:02:40.800 align:middle line:90% otherwise, return C sharp. 00:02:40.800 --> 00:02:47.270 align:middle line:84% And at least maybe it'll get it right sometimes, great. 00:02:47.270 --> 00:02:52.470 align:middle line:84% Now, I will sometimes give you one or two test cases. 00:02:52.470 --> 00:03:00.980 align:middle line:84% So maybe I'll say, assert flip_enharmonic E flat 00:03:00.980 --> 00:03:03.920 align:middle line:90% equals G sharp. 00:03:03.920 --> 00:03:06.500 align:middle line:90% And you see that that works. 00:03:06.500 --> 00:03:11.810 align:middle line:84% Maybe, if I'm very nice, I'll give you two of them. 00:03:11.810 --> 00:03:14.780 align:middle line:84% Up, and you can see that doesn't work. 00:03:14.780 --> 00:03:23.110 align:middle line:84% I am not going to give you all of the interesting and fun test 00:03:23.110 --> 00:03:23.990 align:middle line:90% cases. 00:03:23.990 --> 00:03:27.230 align:middle line:84% Part of the thought process of this class, 00:03:27.230 --> 00:03:29.470 align:middle line:84% part of why you get Humanities credit, 00:03:29.470 --> 00:03:32.660 align:middle line:84% is that you need to be thinking about, 00:03:32.660 --> 00:03:34.280 align:middle line:90% well, what are the weird cases? 00:03:34.280 --> 00:03:37.550 align:middle line:84% OK, I can put in if it's this, it's E flat. 00:03:37.550 --> 00:03:40.930 align:middle line:84% And if it's D sharp, it's E flat, and so on. 00:03:40.930 --> 00:03:46.933 align:middle line:84% Oh, but maybe I need to make sure that this works. 00:03:46.933 --> 00:03:49.750 align:middle line:90% 00:03:49.750 --> 00:03:58.090 align:middle line:84% Or maybe I need to make sure that that works, 00:03:58.090 --> 00:04:00.790 align:middle line:84% or at least that it's a valued answer, huh. 00:04:00.790 --> 00:04:05.500 align:middle line:84% And so part of what you need to do, 00:04:05.500 --> 00:04:09.075 align:middle line:84% is be thinking about how do we write test code, what 00:04:09.075 --> 00:04:11.200 align:middle line:84% are the test cases that Professor Cuthbert is going 00:04:11.200 --> 00:04:15.920 align:middle line:84% to be putting in, such that it's going to challenge how I write? 00:04:15.920 --> 00:04:21.010 align:middle line:84% You'll probably need to rewrite your code as you go. 00:04:21.010 --> 00:04:23.490 align:middle line:90% Great, let's get started. 00:04:23.490 --> 00:04:26.000 align:middle line:90%