How To Write Unit Tests in Python • Pytest Tutorial

[@soumyazyx]

I just loved the way the entire tutorial was planned and executed. The build up was so apt. Loved every bit of it. Thanks for your time and effort. First time here - subscribed

[@pixegami]

Thanks! I did put a lot of thought into planning it, so that it covers all the topics with little wasted effort. I really want to respect my viewer's time - so I really appreciate your comment :)

[@tpag20]

I agree!! this video is best pytest tutorial

[@picassoofai4061]

Agree 💯

[@abhishekanand2782]

This will rank in top 3 videos of all time in Python Unit Testing on KZbin. Had it been a category called 'Python Unit Test' in Academy Awards. It sure will win the Oscar.

[@pixegami]

Thank you! Glad you enjoyed it :)

[@hadisrour5339]

Most underrated channel on KZbin 🙏🏽

[@pixegami]

Thanks! I appreciate that.

[@thatgardnerone]

Coming from a TDD Laravel world, this video is unbelievably helpful in translating lots of that PHP knowledge to Python. Thank you!

[@abelashenafi6291]

Thanks my friend. I can't thank you enough for the knowledge you just shared in just 35 minutes. I had absolutely 0 experience with Unit tests in general but now I really do. I really loved the way you started small and got a bit deeper. This is what most people just don't do. You probably know about Gall's law "All complex systems work, are built on top of simpler systems that worked" Hence, if you want to build a complex system, first build a simple system that works and build on top of that. Thank you. I really mean it. You just got a new subscriber. Abel

[@pixegami]

Thank you for the thoughtful comment :) Glad you found the content useful. Stay tuned, I hope to provide more useful content right here on this channel.

[@sanctipaprichio]

One of the best videos about testing I've ever watched, that's excellent, straight to the point

[@pixegami]

Thanks! That's my goal with these videos :)

[@terryphelps4204]

Nicely done. No bullshit background music, and silly-ass fancy graphics and sound effects. Just good technical knowledge, explained well.

[@Holasticlogger]

In Such a short time you have covered so many features of Pytest...That's Amazing !!!! Loved the video and explanation! Pytest is indeed a powerful test framework !!

[@pixegami]

Glad you liked it :)

[@hichemlaribi252]

Didn't even see the time passing, very good and directly purposed video with no time waisting, thanks a lot

[@nawazhussain1281]

I got this video from google and assumed it was a popular channel. How is it only at 22k. Very well explained vs coming to the video with a bunch of testcases written

[@stankatsion6286]

This is by far one of the best tutorial lessons! It's like every time I'm thinking 'but why that' you continue with explaining exactly what I wanted to know!

[@pixegami]

Really glad to hear that! Thank you :)

[@bryannahrwold5462]

Loved your straight-forward approach and building of functionality as you go. Excellent work. Thanks!

[@pixegami]

Thanks! I hope it helped!

[@bryannahrwold5462]

@@pixegami There is only one thing missing from this video and pretty much everywhere I've looked on the Internet: How to import a function in a directory from a file in another directory at the same depth. This is import for testing packages with the directory structure /src/file with /test/test_file or when one package is accessing another one. A video on that would be terrific!

[@horoshuhin]

really piqued my interest towards the end. great explanation. would love to see part 2 with more advanced test case scenarios. thanks

[@MikeBrown-pt5qw]

Glad this came up on my feed, good tutorial, wish I can like twice. "-s" flag to show print statements even if the test pass was one of the many golden nuggets for me

[@Shawncres2049]

Solid tutorial, great explanation. I like the way it was the closest to hands on learning without having to actually be hands on.

[@pixegami]

Awesome, thank you!

[@r7-wq8ly]

Thank you so much!! I used to think testing was hard and I was afraid to learn, but now I've changed that! Great video🤩

[@pixegami]

Testing seems hard because I think there's not enough education about it! But I'm glad this video helped!

[@vijaybabaria3253]

Would love to see more videos on testing, and integration test to verify end to end testing, thanks 🙏🏼

[@pixegami]

That's a great idea - thanks for the feedback :) I can definitely cover more testing topics.

[@betagroobox]

Yes, please!🙏

[@machinimaaquinix3178]

Hey this was an EXCELLENT and concise intro to pytest! The explanations and examples were so clear, and went beyond the usual test video toy "x + y" drivel . I will strive to use the testing workflow model you demonstrated. The almighty YT algo popped this video in after a recent freecodeacademy Pytest intro video - and honestly, this beats that one by far! And it is three times as long! In fact, I'm linking this video in that video's comments! You rock! And you got a new sub!

[@pixegami]

Thank you for your kind comments :) I try hard to structure the content to be as direct and useful as possible, so I appreciate hearing whenever it helps someone out.

[@furolio]

This channel deserves more subscribers

[@pixegami]

Thanks! I'm glad you think so :)

[@barnabykent6698]

Very practical and accessible tutorial. I enjoy your concise and clear style. This is content with high sound to noise ratio. Subscribed!

[@pixegami]

Thanks! I know everyone is busy and want to learn as quickly as possible, so I aim to keep the content lean. Good to know that the effort is not wasted :)

[@BruceElgort]

This is one of the best videos on pytest I have seen. Thank you for it.

[@pixegami]

Thank you, I appreciate your comment!

[@ddawgncc2]

EXCELLENT Tutorial. Love your approach and style to teaching. Very clear, concise and to the point! Thank you for posting!👍

[@pixegami]

Glad you enjoyed it!

[@JaganMandalapu-g6z]

I hope you take this as a compliment. You are filling in the gap left by Corey Schafer!

[@pixegami]

Thank you! Corey Schafer is a legend and I'm humbled to be compared to them.

[@sleekunique6060]

Great video. Please make more. You explain things without overcomplicating the process.

[@pixegami]

Thanks! More to come. Feel free to suggest topics you'd like to see.

[@Hinkakan]

Great explanation and flow in the video: I find myself sitting with two questions at the end though: 1. Your implementation of the fixture returned one instanciated class. What about if I want to return several values, e.g. environment values, connenction details to databases. How would I return that? Would I return a list of values? Or can I somehow bake it into the function arguments, what information I want to retrieve? 2. I find myself confused on the last part with the Mock module. The way I see it: 1. You instanciate an empty class 2. You call an empty method of this class (none of these fail because both are in fact defined, just have no content) 3. You call Mock to get a value, and you pass in the function to handle the logic. However, the mock_get_item requires an item argument passed to it, yet I do not see you pass anything. Should mock_get_item not receive a list os something that contains the items added to the cart? And in the assertion, you pass in item_database, but the way I read the code, the item_database should still be an empty class since the .get method does nothing yet..

[@pixegami]

Great questions! 1. How do I return a list of values or (anything else) from a fixture? Well, a fixture can return any type of value. So you could have a fixture that returns a tuple. Or you might choose to have a Class or a module that groups together a bunch of different values you want to use together. You are also not limited to using one fixture per test. If you made another fixture called "cart2", then you should be able to use both fixtures in the test by writing: `def test_can_get_total_price(cart, cart2)`. Take a look here for more examples: docs.pytest.org/en/6.2.x/fixture.html 2. You don't see anything being passed in to `mock_get_item` because we never use it directly in the test. We *assign* it to our item_database's "get()" function: "item_database.get = Mock(side_effect=mock_get_item)". Then we call `cart.get_total_price(...)`, which then goes on to call the item_database.get() with our arguments: "total_price += price_map.get(item)": github.com/pixegami/simple-pytest-tutorial/blob/aa65d4b457039dddaeb0a75a359f223a25ec3d09/shopping_cart.py#L23 So when you say " item_database should still be an empty class since the .get method does nothing" - it's actually not true because we *mocked* the get() method to do something for us with this line. We basically 'replaced' the functionality of `item_database.get()`: github.com/pixegami/simple-pytest-tutorial/blob/aa65d4b457039dddaeb0a75a359f223a25ec3d09/test_shopping_cart.py#L42 Hope this helps!

[@pietheijn-vo1gt]

Great video. Could you make a part 2 of this? For example: how to work with context across multiple tests, how to work with scopes, how to work with test data for AI, different types of exceptions etc.

[@pixegami]

Interesting - I hadn't considered a part 2, but I'm keen to hear your use cases for the things you mentioned (particularly about AI testing - do you have a use case in mind for that)?

[@pietheijn-vo1gt]

@@pixegami I worked on a personal project where a pokerbot would receive real images of pokercards and then used a simple CNN to decide which card it was. In order to test the flow I had to import the model, retrieve some test images etc. But I also just wondering in general how to combine unit testing and data science. I really enjoy developing well tested code and these jupyter notebooks are a nightmare to work with when I do anything AI related

[@dr.schlopp4089]

Excellent video! You have a clear talent for teaching and being able to express your ideas thoughtfully and in a manner that is easy to understand. I'm excited to be able to subscribe to a new channel that will soon blow up in popularity once more people see the quality of your content! I'll be able to say, _"I was there..."_ 😂 Subbed!

[@pixegami]

Thanks! I appreciate the support :)

[@gregwoolley]

Excellent tutorial, very helpful! Just one request, is there a way you could position your mic so your keyboard is not so loud (particularly the Return-Key)? Maybe use a 'unidirectional' mic and some type of dampener under your keyboard?

[@pixegami]

Thanks for the feedback! Glad you enjoyed the video. And yes, I agree the keyboard is too loud. Sorry! I've actually upgraded my Mic to a vocal mic, and I'm using a different (softer) keyboard now in my newer videos so I hope it'll feel/sound better for you.

[@davidmendelsohn3932]

Very good tutorial, explained well, clear and at a good pace!

[@janaeshkrish]

It was a great video it helped me a lot to get started with PYTEST, assert ,fixtures and mock. I just loved it

[@mikiyasgetachew77]

very cool Tutorial for pytest. Especially for beginners. Everything is crystal and clear.

[@pixegami]

Thank you! Glad it was helpful!

[@wfacts360]

Finally, a great video to learn pytest. Really, your video helped a lot man!!

[@pixegami]

Thanks! I appreciate the comment.

[@guipe7712]

Great Video. I finally understood most about the pytest framework. Thamks friend

[@timo_b3]

Wow, you covered everything that confused me as a beginner! Thank you

[@pixegami]

Glad it was helpful!

[@sunnybambooflute]

super helpful. Thank you! youtube should rank your video to the 1st position

[@pixegami]

Thanks!

[@sahngcobo]

Very clear and well spoken instructions

[@juliocardenas4485]

Thank you for sharing your talents. It’s well organized, clear, and useful.🙏🏾👨🏽‍💻

[@pixegami]

Thank you! Glad you found it clear!

[@renitur2292]

Excelent video. You are a natural speaker. Thx!

[@pixegami]

Thank you!

[@WistfulOcean]

Very accessible and clear, thank you for that!

[@pixegami]

Glad it was helpful!

[@fatihnri2484]

I rarely comments but this is a great video on PyTest!

[@mohammedshoab2778]

Perfectly explained an important topic!

[@pixegami]

Glad you liked it!

[@TheSaadcheema]

Best tutorial so far on pytest!

[@pixegami]

Thanks! Hope it was useful.

[@ChaosArtist]

Thanks for this tutorial, I'm new to Pytest and this was very helpful.

[@theoryofeverywhere6293]

Extremely well done and clear. Thanks so much for this!

[@pixegami]

You're very welcome!

[@amitsharma5551]

Awesome Video...never seen such a nice explaination of things..love it!!

[@pixegami]

Glad you liked it!

[@marcinbiedron3241]

You are a good teacher, thank you

[@pixegami]

Thank you! 😃

[@MinhBui-h4x]

Excellent video! it's quite clear and concise. By the way, I am curious what VSCode colorscheme you are using in the video?

[@pixegami]

Thank you! I use monokai.pro/ - I've tried a lot of different themes, but I always come back to this one.

[@stannylou1636]

May I ask what operating system you're using? Great tutorial by the way.

[@pixegami]

Thank you! In this video I'm using Ubuntu Linux. It's probably my favourite programming environment, although these days I'm using a Mac because I find I also need a lot of creative software (to make the actual videos).

[@mihaineag3831]

Thanks for the clear and concise info!

[@mryderoc]

Nice job! Great starter for pytest. Thanks

[@pixegami]

Glad you like it!

[@CrashLaker]

awesome! had everything for me to get started. side_effects ftw!

[@pixegami]

You're welcome!

[@VineoClock]

Great Tutorial Mate! Also, was wondering which OS did you use for recording? Seems v cool.

[@pixegami]

Thanks mate! Glad you enjoyed it. :) In this video I'm using Ubuntu with a customized terminal. If you're interested in setting it up, I've got a video on that: kzbin.info/www/bejne/i6e8ZpR8fbOie9k But these days I'm actually doing everything on an M1 Mac (just because Ubuntu doesn't support Adobe which I use for editing).

[@rosscoguitar]

Thank you for this video. You've done a really great job of explaining these concepts.

[@pixegami]

Thanks! I appreciate the comment :)

[@gasparottogui]

Great tutorial! Simple and effective. Thanks!

[@pixegami]

Glad it was helpful!

[@shelleycurrie764]

Great, thanks you covered enough for me to get going.

[@pixegami]

You're welcome! Good luck.

[@MrAndyG67]

Very useful intro, thanks.

[@pixegami]

Glad it was helpful!

[@ChongSun]

Thanks! Nice TDD tutorial.

[@pixegami]

Glad you liked it!

[@chriskeo392]

You're a great teacher. Wonder if you have a tutorial on app structure too?

[@pixegami]

Not yet, but I'll note it down as an idea that my audience wants! Thank you.

[@olaniyanayodele5986]

Great video. Just learnt pytest. Mind sharing your vs code theme setup?

[@pixegami]

Thanks! For VSCode I use the paid "Monokai Pro" theme, but they do have a free trail. Other themes I've enjoyed in the past are "Nord" and "Ayu".

[@harryz3314]

What is your keyboard? It sounds great!

[@pixegami]

In this video I just used a DURAGOD keyboard with blue-key switches. I've since changed now to a Moonlander keyboard with brown switches. They keyboards don't really make too much difference to me as long as they are the thicker mechanical types.

[@Themuralisp]

very nicely explained. Thank you

[@DaCosmoz]

This was a very helpful and clear tutorial, thank you very much!

[@pixegami]

Glad to hear it!

[@sebastiancontreras3300]

Thank you! U totally domain the subject entirely

[@pixegami]

Glad it was helpful!

[@jtech8959]

Hi, great video thanks! Could you explain why you didnt or when to use mock.patch instead of what you did here creating an instance of the db and return a mock.

[@pixegami]

Great suggestion! `mock.patch` works too, and is probably a good way to do it. I didn't choose to use it here mainly because I wanted to make the relationship between the mock and the dependency clearer. Introducing mock.patch would introduce some new mental concepts (with it being a decorator), and I didn't want that at this stage in the tutorial. Now, in actual real projects I've used mock.patch before, but it started to become annoying when there's maybe 5-6 things I needed to patch for one test. A lot of nesting, ordinal arguments, and a lot of repetition across various test cases. I am now learning towards fixtures instead, to set up more complex mock behavior.

[@adhavarrv]

Thanks for a great and simple tutorial on PyTest!

[@pixegami]

Glad it was helpful!

[@filmedbyjulia124]

helpful video on unit testing! Thank you!

[@ukplaymaker15]

Thank you for this amazing tutorial.

[@pixegami]

I hope it was helpful!

[@rasheedibraheem6839]

What a great tutorial! Thank you!

[@pixegami]

Glad it was helpful!

[@mohammederifaimaamir7087]

Thank you so much, u've made my life easier

[@pixegami]

Awesome! Glad to hear that!

[@junhuama68]

at 8:20 here you are teasing one function of the instance(add) but also depends on another function of that instance(size). I thought that we are suppose to isolate each test.

[@947ihi]

I can't thank you enough for this video🙌 This helped me so much!

[@pixegami]

Glad it helped!

[@winnumber101]

very high quality video

[@pixegami]

Thanks. I appreciate it!

[@davidbalague9311]

Excellent and comprehensive tutorial, very well explained and accessible. Best ever! Good Job!!

[@fabiohenriqueteixeira5566]

Excellent content!!!

[@hardcorewithin]

great video! what are you using as a terminal ? I love the way it displays the cwd as shadow instead of showing the full path , can you please share the theme name ? thanks !

[@ziad9533]

A very useful video, thank you!

[@pixegami]

Glad it was helpful!

[@krishanunayek785]

Hello, This is really very good content. It helped me a lot to implement unit test cases. I am trying to implement some retry mechanism (using HTTPadapter , retry package) when the given http errors (500,502,503,504) occur. Now I am not able to implement the retry mechanism as well as the unit testcases for the same. It would be really helpful if you create some video on the same topic.

[@magorzatastolarska4274]

Great tutorial! Thanks a lot.

[@pixegami]

You're welcome!

[@xiliu1842]

Very Nice video, Thanks man!

[@pixegami]

Glad you liked it!

[@dhartdata5998]

very informative. Thanks

[@nakawesijuliet2363]

Very helpful to a beginner like me,thanks. can you help me on how to integrate zoom in a django project?

[@pixegami]

Sorry I haven't done any Django projects yet but it's on my list!

[@nakawesijuliet2363]

Cool@@pixegami

[@امینجمالی-خ9ص]

Thanks for your time and effort awesome video!!!!

[@pixegami]

Thank you, I appreciate your comment!

[@shmuelk3018]

Amazing, I really enjoyed it

[@pixegami]

Awesome, thank you!

[@aravinddt16]

Well structured!

[@pixegami]

Thank you!

[@krishj8011]

Awesome Tutorial... very useful...

[@pixegami]

Thanks! Glad you found it useful 😊

[@jinettew.3192]

Really nice intro.

[@pixegami]

Thanks!

[@Confusedcapybara8772]

That keyboard sounds good 👌 specs?

[@pixegami]

Haha I've used a lot of keyboards so I'm not sure which one specifically I used in this video. I think it was probably this one, with the blue Cherry switches: amzn.asia/d/3uXqhmU

[@danielrossano3322]

keep up the good work!

[@pixegami]

Thanks for the encouragement!

[@shreshtapagidimarry9603]

Which ZSH theme is that ? I would like to install the same. Looks amazing,

[@pixegami]

I have a video and a GitHub repo covering the Ubuntu ZSH theme I use: github.com/pixegami/terminal-profile

[@hj-wl4vk]

What's your vscode theme? It 's great!

[@python360]

20:07 You can also use "pytest -k test_can_get_total_price"

[@pixegami]

Ah, thanks for calling out!

[@AndresRodriguez-vv3fs]

Hey! Loved the video, but could you keep speaking when you code? Helps a lot when coding along! Much love

[@pixegami]

Thanks for the feedback! I'll definitely try to keep talking more - I need a lot of practice talking and coding at the same time 😅

[@cOnT3ST]

Huge thanks for the vid.

[@pixegami]

Glad it helped

[@raphaelhunold6812]

good video. You earn a new follower

[@pixegami]

Thanks and welcome!

[@ChanceMinus]

Excellent! Thank you.

[@galnadjar]

amazing video thank you!

[@python360]

Really useful, thank you!

[@pixegami]

Glad it was helpful!

[@vietnamdang1917]

Hi Pixegami, Python is totally new to me. I am very interested in learning it. Would you mind sending me a link to or show me how to download/install Python to my laptop? Thanks in advance.

[@pixegami]

Python is a great programming language to learn! I have a complete playlist on a learning roadmap and how to install it and learn all the basics here: kzbin.info/aero/PLZJBfja3V3Rsbiz84Z63IXnTQZH_Rnfuo&si=-hMurnRNSf2s7J_m

[@dbzkidkev2]

Great video but question, why didnt you use monkeypatch?

[@pixegami]

Good call. I wanted to start off with more primitive tools, and more generalisable knowledge. Mocking and stubbing is pretty widely used, but I think patching is more prominent in Python testing. I'm also not a fan of positional arguments for the mocked items, I think fixtures afford more precision and flexibility.

[@rohithdiya]

Thanks very useful :)

[@pixegami]

Glad it was helpful!