TDM 30100: Project 9 — 2022

Motivation: Python is an incredible language that enables users to write code quickly and efficiently. When using Python to write code, you are typically making a tradeoff between developer speed (the time it takes to write a functioning program) and program speed (how fast your code runs). Python code does not have the advantage of easily being compiled to machine code and shared. In Python, you need to learn how to use virtual environments, and it is good to have an understanding of how to build and push a package to pypi.

Context: This is the second in a series of 3 projects that focuses on setting up and using virtual environments, and creating a package. This is not intended to teach you everything, but rather, give you some exposure to the topics.

Scope: Python, virtual environments, pypi

Learning Objectives

Explain what a virtual environment is and why it is important.
Create, update, and use a virtual environment to run somebody else’s Python code.
Create a Python package and publish it on pypi.

Make sure to read about, and use the template found here, and the important information about projects submissions here.

Dataset(s)

The following questions will use the following dataset(s):

/anvil/projects/tdm/data

Questions

Question 1

In the previous project, the author made a mistake that may have caused some confusion. Many apologies! Therefore, this first question is going to be a review of what was accomplished in the previous project.

Like the previous project, this project will consist primarily of your Jupyter notebook, with screenshots of your terminal after running commands. bash cells will not work properly due to the way our environment is setup. For this reason, it is important to first open a terminal from within Jupyter Lab, to run commands, take screenshots, and display the screenshots in your Jupyter Notebook (your .ipynb file).

Activate our "base" image, so we start with Python 3.10 instead of Python 3.6:

module load python/jupyterlab

# which interpreter is active?
which python3

# list our current set of python packages using pip
python3 -m pip list

Create a virtual environment:

# create the virtual environment named p9q1 in your $HOME directory
python3 -m venv $HOME/p9q1

# check out what files and folders the environment consist of
ls -la $HOME/p9q1

# which python are we currently using?
which python3

# which packages?
python3 -m pip list

# activate our newly created virtual environment
source $HOME/p9q1/bin/activate

# which python are we currently using?
which python3

# what packages do we have available?
python3 -m pip list

Activate a virtual environment:

source /path/to/my/virtual/environment/bin/activate

# for example, if our virtual environment was called myvenv in the $HOME directory
source $HOME/myvenv/bin/activate

Deactivate a virtual environment:

deactivate
which python3 # will no longer point to interpreter inside the virtual environment folder

Install a single package to your virtual environment:

# first activate the virtual environment
source $HOME/p9q1/bin/activate

# install the requests package
python3 -m pip install requests

Pin dependencies, or make the current virtual environment rebuildable by others:

# first activate the virtual environment you'd like to pin the dependencies for
source $HOME/p9q1/bin/activate

# next, create a requirements.txt file with all of the packages, pinned
python3 -m pip freeze > $HOME/requirements.txt

Build a fresh virtual environment using someone else’s pinned dependencies:

# create the blank environment
python3 -m venv $HOME/friendsenv

# activate the environment
source $HOME/friendsenv/bin/activate

# install the _exact_ packages your friend had, using their requirements.txt
python3 -m pip install -r $HOME/requirements.txt

# verify the packages are installed
python3 -m pip list
python3 -m pip freeze

Delete a virtual environment you don’t use anymore:

# IMPORTANT: Ensure you do NOT have a typo
rm -rf $HOME/p9q1

Run through some of those commands, until it "pretty much" clicks. Take and include at least a couple screenshots — no need to include everything if you feel comfortable with everything shown above.

Make sure to take screenshots showing your input and output from the terminal throughout this project. You final submission should show all of the steps as you walk through the project.

Items to submit

Code used to solve this problem.
Output from running the code.

Question 2

Wow! When you look at all of that information from question (1), virtual environments aren’t really all that much work to use!

Okay, if you haven’t already done something similar (some of you may have), I imagine this next statement is going to be pretty exciting. By the end of this project you will create a new virtual environment and pip install your very own package, from pypi.org/!

Let’s start by writing the heart and soul of your package — a function that, given an imdb id, scrapes and returns the rating.

Create a new virtual environment to work in called question02.
Install one or more of the following packages to your environment (you will probably want at least 2 of these to write this function): requests, beautifulsoup4, lxml.
Write and test out your function, get_rating.

Please include screenshots of the above steps, all the way until the end where a rating should print for an imdb title.

For example, www.imdb.com/title/tt4236770/?ref_=nv_sr_srsg_0 would have an imdb title id of tt4236770. We want the functionality to look like the following.

get_rating("tt4236770")

output

8.7

You can use the following as a skeleton — just fill in part of the xpath expression.

import requests
import lxml.html

def get_rating(tid: str) -> float:
    """
    Given an imdb title id, return the title's rating.
    """
    resp = requests.get(f"https://www.imdb.com/title/{tid}", stream=True)
    resp.raw.decode_content = True
    tree = lxml.html.parse(resp.raw)
    element = tree.xpath("//div[@data-testid='FILL THIS IN']/span")[0]
    return float(element.text)

Items to submit

Code used to solve this problem.
Output from running the code.

Question 3

The next step in this process is to organize your files. Let’s make this a simple, barebones setup.

First, let’s decide on the package name. Choose a package name starting with tdm-. For example, tdm-drward. Create a project directory with the same name as you package. For example, mine would be the following.

mkdir $HOME/tdm-drward

Great! This will be the name you use to install via pip. So in my case, it would be python3 -m pip install tdm-drward.

Next, create 3 new files inside the tdm-drward (or equivalent) folder.

LICENSE
pyproject.toml
README.md

The first file is a simple text file containing the text of your license. You can use choosealicense.com/ to choose a license and paste the text of the license in your LICENSE file.

The third file is a README.md — a simple markdown file where you will eventually keep the important instructions for your package. For now, go ahead and just leave it blank.

The second file is a critical file that will be used to specify various bits of information about you package. For now, you can leave it blank.

Next, create a new directory inside the $HOME/tdm-drward package directory. Name the directory whatever you want. This will be the name that is used when importing your package. For example, I made $HOME/tdm-drward/imdb. For my package, I will do something like:

import imdb

# or

from imdb import get_rating

Finally, copy and paste your get_rating function into a new file called imdb.py, and drop imdb.py into $HOME/tdm-drward/imdb (or your equivalent package path). In addition, create another new file called __init__.py in the same directory. Leave it blank for now.

Your directory structure should look something like the following.

tree $HOME/tdm-drward

directory structure

tdm-drward
├── imdb
│   ├── imdb.py
│   └── __init__.py
├── LICENSE
├── pyproject.toml
└── README.md

1 directory, 5 files

Fantastic! Now, let’s create a new virtual environment called p9q3, activate the environment, and run the following.

python3 -m pip install -e $HOME/tdm-drward

This will install the package to your p9q3 virtual environment so you can test it out and see if it is working as intended! Let’s go ahead and test it to see if it is doing what we want. Run python3 to launch a Python interpreter for our virtual environment. Run the following Python code from within the interpreter.

import imdb # works
print(imdb.__version__) # error
imdb.get_rating("tt4236770") # error
imdb.imdb.get_rating("tt4236770") # works
from imdb import get_rating # error
get_rating("tt4236770") # error

What happens? Well, it isn’t behaving exactly like we want, but we can import things.

import imdb.imdb
imdb.imdb.get_rating("tt4236770") # will work

from imdb.imdb import get_rating
get_rating("tt4236770") # will also work

Here is the critial part, the __init__.py file. Any directory containing a __init__.py file is the indicator that forces Python to treat the directory as a package. If you have a complex or different directory structure, you can add code to __init__.py that will clean up your imports. When a package is imported, the code in __init__.py is executed. You can read more about this here.

Go ahead and add code to __init__.py.

from .imdb import *

__version__ = "0.0.1"

print("Hi! You must have imported me!")

Re-install the package.

python3 -m pip install -e $HOME/tdm-drward

Now, launch a Python interpreter again and try out our original code.

import imdb # works, prints your message
print(imdb.__version__) # prints 0.0.1
imdb.get_rating("tt4236770") # works
imdb.imdb.get_rating("tt4236770") # still works
from imdb import get_rating # works
get_rating("tt4236770") # works

Wow! Okay, this should start to make a bit more sense now. Go ahead and remove the silly print statement in your __init__.py — we don’t want that anymore!

Finally, let’s take a look at the pyproject.toml file and fill is some info about our package.

pyproject.toml

[build-system]
requires      = ["setuptools>=61.0.0", "wheel"]
build-backend = "setuptools.build_meta"

[project]
name = "FILL IN"
version = "0.0.1"
description = "FILL IN"
readme = "README.md"
authors = [{ name = "FILL IN", email = "FILLIN@purdue.edu" }]
license = { file = "LICENSE" }
classifiers = [
    "License :: OSI Approved :: MIT License",
    "Programming Language :: Python",
    "Programming Language :: Python :: 3",
]
keywords = ["example", "imdb", "tutorial", "FILL IN"]
dependencies = [
    "lxml >= 4.9.1",
    "requests >= 2.28.1",
]
requires-python = ">=3.10"

Be sure to fill in the "FILL IN" parts with your information! Lastly, make sure to specify any other Python packages that your package depends on in the "dependencies" section. In the provided example, I require the package "lxml" of at least version 4.9.1, as well as the"requests" package with at least version 2.28.1. This makes it so when we pip install our package, that these other packages and their dependencies are also installed — pretty cool!

Items to submit

Code used to solve this problem.
Output from running the code.

Question 4

Okay, to the best of our knowledge our package is ready to go and we want to make it publicly available to pip install. The next step in the process is to register an account with test.pypi.org here. Take note of your username and password.

Next, confirm your email address. Open up the email you used to register and click on the link that was sent to you.

Finally, its time to publish your package to the test package repository!

In order to build and publish your package, we need two packages: build and twine. Let’s setup a virtual environment and install those packages so we can use them!

Deactivate any environment that may already be active by running: deactivate.
Create a new virtual environment called p9q4.
Activate your p9q4 virtual environment.
Use pip to install build and twine: python3 -m pip install build twine.
Build your package.
python3 -m build $HOME/tdm-drward
Check your package.
python3 -m twine check $HOME/tdm-drward/dist/*

You may get a warning, that is ok.
Upload your package.
python3 -m twine upload -r testpypi $HOME/tdm-drward/dist/*

You will be prompted to enter your username and password. Enter the credentials associated with your newly created account.

Congrats! You can search for your package at test.pypi.org. You are ready to publish the real thing!

Items to submit

Code used to solve this problem.
Output from running the code.

Question 5

Okay, register for a Pypi account here.

Next, verify your account by checking your associated email account and clicking on the provided link.

At this stage, you already built your package using python3 -m build, so you are ready to simply upload your package!

Deactivate any currently active virtual environment by running: deactivate.
Create a new virtual environment called p9q5.
Activate your p9q5 virtual environment.
Use pip to install twine: python3 -m pip install twine.
Upload your package: python3 -m twine upload $HOME/tdm-drward/dist/*

You will be prompted to enter your username and password. Enter the credentials associated with your newly created account.
Fantastic! Take a look at pypi.org and search for your package! Even better, let’s test it out!
Your p9q5 virtual environment should still be active, let’s pip install your package!
```
python3 -m pip install tdm-drward
```
Of course, replace tdm-drward with your package name!
Finally, test it out! Launch a Python interpreter and run the following.
```
import imdb
imdb.get_rating("tt4236770") # success!
```

Congratulations! I hope you all feel empowered to create your own packages!

Make sure to take screenshots showing your input and output from the terminal throughout this project. You final submission should show all of the steps as you walk through the project.

Items to submit

Code used to solve this problem.
Output from running the code.

Please make sure to double check that your submission is complete, and contains all of your code and output before submitting. If you are on a spotty internet connection, it is recommended to download your submission after submitting it to make sure what you think you submitted, was what you actually submitted.

In addition, please review our submission guidelines before submitting your project.