Here are all the comments that your Udacity Code Reviewer had about your code...

Transcription

1 Here are all the comments that your Udacity Code Reviewer had about your code Line 96 in finalproject.py is Critical hexagon.exitonclick() Reviewer says: The last line of the draw function of the hexagon class throws an exception. The exitonclick() method is called on the hexagon object instead of on turtle like the other methods. This method does not exist on the hexagon object so it will throw an exception and exit the program when called. Line 73 in finalproject.py is Critical star=turtle.turtle() star.color(self.shape_color)#takesuserinputedcolorforthe drawing. star.goto(self.x,self.y) Reviewer says: A bug was found when drawing objects in a position other than (0, 0). When the pen/turtle moves to the specified position there is a line drawn before the shape is drawn. Consider looking at the penup() and pendown() methods so the extra line is not drawn. Line 102 in finalproject.py is Nitpick print("whatcolorwouldyoulikeyourdrawingtobe?")#promptstheuser tochooseacolortodrawtheshapewith. user_color=raw_input()

2 print("wherewouldyouliketodrawtheshape?(inputx coordinate)")#promptstheusertochoosethexcoordinateforthe turtle'sstartingposition. user_x=raw_input() print("wherewouldyouliketodrawtheshape?(inputy coordinate)")#promptstheusertochoosetheycoordinateforthe turtle'sstartingposition user_y=raw_input() Reviewer says: There are a number of lines in the code to prompt the user for things like color and position that is duplicated for every shape type. These could be pulled up and saved before the user input check on shape so that they are only in one place. Avoiding duplication in code reduces maintenance costs (any updates are made in one place) as well as the potential for errors. This is sometimes referred to as the "Don't Repeat Yourself" Principle (or DRY) if you'd like to look further into that online. Line 5 in finalproject.py is Nitpick classtriangle(): #Initializationfunction(requires3inputswhencalled) def init (self,shape_color,x_pos,y_pos): self.shape="triangle" self.shape_color=shape_color self.x=x_pos self.y=y_pos #Drawfunction.Usesturtletodrawtheshapeoftheclass triangle=turtle.turtle() triangle.color(self.shape_color)#takesuserinputedcolorfor thedrawing. triangle.goto(self.x,self.y)#takesuserinputedcoordinatesand setsthestartingpositionoftheturtle. foriinrange(1,4): triangle.forward(100) triangle.right(120) turtle.exitonclick() Reviewer says: Although I think your classes are a great start as they are clean and easy

3 to follow, there is also some duplication within them. Each class stores the same member variable information and performs some of the same functions in their draw methods. Try to think of a way to reduce this duplication for the reasons stated earlier regarding code duplication (e.g. if you have to make a change it is much less error prone to do it in one place). Line 1 in finalproject.py is Nitpick #importsturtlelibraryintotheprogram. importturtle #classtriangle classtriangle(): #Initializationfunction(requires3inputswhencalled) def init (self,shape_color,x_pos,y_pos): self.shape="triangle" self.shape_color=shape_color self.x=x_pos self.y=y_pos #Drawfunction.Usesturtletodrawtheshapeoftheclass triangle=turtle.turtle() triangle.color(self.shape_color)#takesuserinputedcolorfor thedrawing. triangle.goto(self.x,self.y)#takesuserinputedcoordinatesand setsthestartingpositionoftheturtle. foriinrange(1,4): triangle.forward(100) triangle.right(120) turtle.exitonclick() Reviewer says: I see that you've attempted to document your code and that's great! There are a few things to keep in mind when documenting your python code. There should be a space between the '#' and the text of the comment (e.g. # comment) built in or library functions do not need explanation about what they do (e.g. #imports turtle library into the program < this is not necessary, a python developer will know what 'import'

4 means); the same is true for things like the init method avoid inline comments (comments on the same line as a piece of code) as per the python style guide ( 0008/#block comments) documenting classes and methods using block comments focus more on the "why" in comments as opposed to the "what" or the "how"; often times a developer can see what is being done in the code, but it is the why that can be elusive and needs further clarification; the other danger is that if the "what" or "how" is being explained, but the code does not match up it may not be clear if there was a code change, but the comments weren't updated or if it is actually a bug watch for grammatical or spelling errors; the typo 'inputed' is used in many places Some of the above points are highlighted or explained further in the Python Style Guide (a.k.a PEP 8) and is a good resource for learning more about python coding conventions and establishing some good python coding habits. It can be found here: /#introduction Line 99 in finalproject.py is Awesome print("chooseatriangle,square,circle,starorhexagontodraw") #Promptstheusertochooseashapetodraw. user_input=raw_input() if(user_input=="triangle"):#teststheuserinputtofindthe inputedshape. print("whatcolorwouldyoulikeyourdrawingtobe?")#prompts theusertochooseacolortodrawtheshapewith. user_color=raw_input() print("wherewouldyouliketodrawtheshape?(inputx coordinate)")#promptstheusertochoosethexcoordinateforthe turtle'sstartingposition. user_x=raw_input() print("wherewouldyouliketodrawtheshape?(inputy coordinate)")#promptstheusertochoosetheycoordinateforthe turtle'sstartingposition user_y=raw_input() Reviewer says: I think it's great that you are prompting the user for information about what to draw! Including the shape, color and position is a nice touch.

5 Line 98 in finalproject.py is Nitpick whiletrue: print("chooseatriangle,square,circle,starorhexagontodraw") #Promptstheusertochooseashapetodraw. user_input=raw_input() if(user_input=="triangle"):#teststheuserinputtofindthe inputedshape. print("whatcolorwouldyoulikeyourdrawingtobe?")#prompts theusertochooseacolortodrawtheshapewith. user_color=raw_input() print("wherewouldyouliketodrawtheshape?(inputx coordinate)")#promptstheusertochoosethexcoordinateforthe turtle'sstartingposition. user_x=raw_input() print("wherewouldyouliketodrawtheshape?(inputy coordinate)")#promptstheusertochoosetheycoordinateforthe turtle'sstartingposition user_y=raw_input() triangle=triangle(user_color,int(user_x),int(user_y))#calls initializationfunctionfortrianglewiththerequiredinputs. triangle.draw()#callsthedrawfunctionwithinthetriangleclass todrawthechosenshape. Reviewer says: Here are a few suggested improvements to the code that handles user input: it'd be lovely if there was a way for the user to exit the program gracefully (like an 'exit' option on the shape prompt, for example) something that may be good to know also is that you can pass in a prompt to the raw_input() call and it will be displayed to the user instead of the separate print statement ( any time a program is prompting the user for input there is a chance that it may get data it doesn't expect; the code should be able to handle unexpected input so that it doesn't crash; the submitted code is doing this for the shape input; if there is something entered that is not one of the approved shapes it lets the user know (which is great) and re prompts the user. That idea just needs to be extended to the input for color and co ordinates; You may want to also check out exception handling as that is a great way to handle unexpected conditions the if/else statements work fine and everything is neatly organized, but if you are feeling

6 adventurous I would recommend looking how to handle the selection in a "more pythonic way"; take a look here if you're interested: pythonic way to implement switchcase statem ents Line 101 in finalproject.py is Awesome if(user_input=="triangle"): Reviewer says: The code checks user input for shape type and lets user know if an invalid input was entered; it then re prompts the user for a shape. That's great! Line 5 in finalproject.py is Nitpick classtriangle(): classsquare(): classcircle(): classstar(): classhexagon(): Reviewer says: Class names should follow CamelCase convention as per PEP 8 ( 0008/#class names) e.g. class Triangle(): Line 19 in finalproject.py is Nitpick foriinrange(1,4): Reviewer says: A minor style nitpick: There should be a single space after commas in function calls ( 0008/#whitespace in expressions and statements) e.g. range(1, 4):

7 This is also to be consistent with the other function calls in the code. Line 104 in finalproject.py is Nitpick print("wherewouldyouliketodrawtheshape?(inputxcoordinate)") #Promptstheusertochoosethexcoordinatefortheturtle'sstarting position. user_x=raw_input() print("wherewouldyouliketodrawtheshape?(inputy coordinate)")#promptstheusertochoosetheycoordinateforthe turtle'sstartingposition Reviewer says: Another minor nitpick: some of the code lines are a bit long; maximum line length is specified in the style guide ( 0008/#maximum line length) note: this may be fixed by other edits, like reducing inline comments and is mentioned here for future reference Line 15 in finalproject.py is Nitpick turtle.exitonclick() Reviewer says: This is more of a design consideration and not an error. You may want to consider moving the clearscreen and exitonclick functionality out of the draw method of the classes as they are technically not items that are needed to draw the shape. Why it matters is probably best explained with an example: if this was code that was going to be included and used by other code that may want to draw those shapes and you wanted to draw multiple shapes you would not be able to do so as every new shape would clear the screen. This is just something to consider when thinking about designing software. A good question to ask is, "does the method/class do what is expected?" This kind of concept is also known as the "Single Responsibility Principle" or SRP and if you search for that online there are many resources and discussions on the subject. The basic idea is that classes should have a single "responsibility" and "do one thing". This

8 leads to easier maintenance and more robust classes. In this case one direction the code could go is first pulling out the clearscreen and exitonclick into the code that calls the draw method (in the while loop) Line 5 in finalproject.py is Awesome classtriangle(): #Initializationfunction(requires3inputswhencalled) def init (self,shape_color,x_pos,y_pos): self.shape="triangle" self.shape_color=shape_color self.x=x_pos self.y=y_pos #Drawfunction.Usesturtletodrawtheshapeoftheclass triangle=turtle.turtle() triangle.color(self.shape_color)#takesuserinputedcolorfor thedrawing. triangle.goto(self.x,self.y)#takesuserinputedcoordinatesand setsthestartingpositionoftheturtle. foriinrange(1,4): triangle.forward(100) triangle.right(120) turtle.exitonclick() Reviewer says: Grouping the information needed for drawing the shape into classes is really good. Except for the clearscreen and exitonscreen call the draw function also focuses on drawing the shape so it's very close to following the Single Responsibility Principle. The code is easy to follow and understand. Because the code was easy to follow and understand it made it easier to find areas for improvement, so good job!