Skip to main content

Getting Started with Python

General Information​

Submitting to the Auto-Grader

For auto-grading homework assignments in the course, we use Gradescope.

General Submission Info​

When submitting files to Gradescope, you need to submit all the files you want graded at once.

You can do this in several ways:

  • Select all files you want to submit and drag and drop them in the submission area when prompted.
  • Browse your files when prompted by Gradescope and select all files you want to submit.
  • Directly compress all the files you want to submit into a zip file (zip file name does not matter), and submit that zip file via drag-and-drop or browsing for it.
  • Compress a folder containing the files you want to submit into a zip file (zip file name does not matter), and submit that zip file via drag-and-drop or browsing for it.

Gradescope will look for files with specific names, and those names are case-sensitive. So if in the instructions we ask for a file named hello.py, then Gradescope will not recognize Hello.py, hello.txt, or hello.py.txt.

Group Submissions​

When a group of people is submitting an assignment, only one person should submit the solution.

They should then add the other members to that submission. On the Gradescope page for a submission there should be a "+ Add Group Member" button by the name in the upper-right.

This is important because if multiple people submit, our similarity checker will see identical submissions and flag that.

Unlimited attempts​

You have unlimited attempts for our auto-graded assignments.

This means that you should submit early and often in order to be confident that code you are writing as you go passes all of our tests.

Academic Honesty

All work that is completed in this assignment is your own group's. You may talk to other students about the problems you are to solve, however, you may not share code in any way, except with your partner(s). What you submit must be your own group's work.

You may not use any code that is posted on the internet. If you are not sure it is in your best interest to contact the course staff. We will be using software that will compare your code to other students in the course as well as online resources. It is very easy for us to detect similar submissions and will result in a failure for the exercise or possibly a failure for the course. Please, do not do this. It is important to be academically honest and submit your work only. Please review the UMass Academic Honesty Policy and Procedures so you are aware of what this means.

Copying partial or whole solutions, obtained from other students or elsewhere, is academic dishonesty. Do not share your code with your classmates, and do not use your classmates' code. If you are confused about what constitutes academic dishonesty you should re-read the course policies. We assume you have read the course policies in detail and by submitting this project you have provided your virtual signature in agreement with these policies.

About​

Almost as a tradition, the first program someone learning to write code is likely to write is some variation of a Hello World program.

So that's what you're doing! The real "assignment" here is more about installing things, setting up a programming environment, learning about the auto-grader, et cetera.

Learning Objectives​

  1. Install Python
  2. Set up Integrated Development Environment (IDE)
  3. Write first program in python
  4. Become more familiar with Gradescope

Estimated Size​

One file, with one line of code and three lines of comments.

Assignment​

We're going to really break this one up into pieces.

For this--and only this--assignment, you must work alone. You are totally welcome to talk to people nearby, everyone just needs to make their own submissions We want everyone to have everything installed and in working order, and to know the the Gradescope process looks like.

0.1. Install Python​

Follow the relevant guide on the website to install Python.

0.2. Set up VSCode​

Follow these guides on the website to install and set of the editor, VSCode.

1. Make a file named hello.py​

Now the actual assignment can begin.

Make a folder for this assignment somewhere of your choosing.

Open that folder in VSCode (Open VSCode and select File > Open Folder, navigate to that folder you made and select it).

Make a new file named hello.py (select File > New File, and name it when prompted).

2. Add author information to hello.py​

We want you to put your name, UMass email, and who you worked with at the top of all assignments so that we know who wrote each file (when working in groups) and to help us connect each student with their email on Gradescope (sometimes non-UMass emails are used, and it's difficult to find the UMass one in that case)

That can be done with comments. Comments are lines that are ignored by the computer.

You start a comment (in python) with the # character. Anything on that line after that character is ignored.

So specifically, we want:

  • # Author or # Authors to be the start of the first line of the file.
  • # Email or # Emails to be the start of the second line of the file.
  • # Spire ID or # Spire IDs to be the start of third line of the file.
  • each of the above followed by the relevant information.

For example, the first three lines of a file may look like this:

# Author: Jared Yeager
# Email: jyeager@cs.umass.edu
# Spire ID: 31415926

Note: this is expected of every file going forward.

3. Add print() statement to hello.py​

Finally, the actual code.

After the comments from earlier add the line

print("Hello, World!")

print(), as you may have guessed, is a command that prints the input (to the terminal). The input is surrounded by parentheses.

The quotes around the input, "Hello, World!", indicate it is text (a string, more technically).

Note: When showing code in general, we will use a mono-spaced font. When talking about "commands" like print(), we will have the () afterward to denote that it is a command. (Technically, these are called "functions", but that lecture is next week.)

Testing

While we have auto-graded tests for you, we don't want to encourage dependence on the auto-grader. We want to try and impart testing and debugging skills so that you are equipped in any circumstance.

To that end, we will have testing recommendations/suggestions where we can, so that you can test your code.

In this case, running the code and making sure "Hello, World!" is printed is the natural thing to do. Running code and making sure it does what you expect is the essence of testing. (Finding out where it first deviates from what you expect is the essence of debugging)

To run the code, open the built-in terminal (select Terminal > New Terminal) and type in python3 hello.py in the terminal.

You should now see:

$ python3 hello.py
Hello, World!

This $ sign notation is not literal, it represents lines you entered input on.

4. Submit hello.py to Gradescope​

Log in to Gradescope, select the relevant assignment, and submit hello.py

Gradescope has a guide on submitting assignments like this.

Note: in general, you will submit all .py files for a relevant assignment at once.

Extra Details​

There will be some times where we like to provide extra details or information--stuff that may not be covered in the course itself or that will be covered later. None of this is necessary to know at this point.

The Code​

It's all well and good to have you write print("Hello, World!"), but what do the pieces of this mean?

print() is a "function". We will learn more about functions next week. But for some intuition: you can think of them as commands; you can think of them as ways to invoke re-usable, named snippets of code; or you can think of them as black boxes that take inputs (like functions in math), spit out outputs (like functions in math), and have side effect (un-like function in math). In this last view, print() takes in something to print, returns nothing, and has the side-effect of printing the input.

"Hello, World!" is a "string". We should have already learned about them (but in case not...). But for some intuition: there is a notion of numbers and text as different "types", strings are the text-like type. To indicate something is text, we wrap it in quotation mark. Note: these are straight quotation marks. "text" will work, 'text' will also work; the following will not work: `text`, “text”, and ‘text’. No back-ticks, nothing that curls.

And so print("Hello, World!") passes the string (text) "Hello, World!" to the function print(), which prints it.

The Terminal​

What is the terminal?

The terminal is an interface to out computers that allows us to give it commands through text, which it will make a program to accomplish. It also allows us to give those programs input, and for those programs to give us output.

It is a tool for us to run and interact with programs.

Running the Code​

What does the terminal command python3 hello.py mean?

The python3 part is a command that says "run the python 3 interpreter".

The hello.py part is giving the file hello.py to the python 3 interpreter to, well, interpret.

The command can be read as "run python3 with input hello.py.