Dictionary Comprehension - Create Complex Data Structures Step by Step

Welcome to the best tutorial I've ever filmed!!! 😍😍😍
Today we will talk about Dictionary Comprehension which is a very clever technique to construct dictionaries from different collections of data.
We will start with a 🐍 basic code example 🐍 (00:47 - 03:47) and we will move on to practice our new set of skills with 3 FUN and USEFUL exercises:
1. Superheroes exercise:
correct a distorted dictionary (03:47)
2. Genetics exercise:
create a random DNA sequence by pairing bases (08:26)
3. Authentication exercise:
create a dictionary of users with random passwords (14:55)

⭐ Get complete tutorial code ⭐

🎥 RELATED TUTORIALS 🎥
---------------------------------------------
⭐ Python For Loops for Beginners:
⭐ List Comprehension:

⏰ Time Stamps ⏰
--------------------------------
00:00 - intro
00:21 - tutorial plan
00:47 - create dictionary with for loops
01:04 - zip function approach
01:37 - range function approach
02:05 - dictionary comprehension with zip
02:47 - dictionary comprehension with range
03:17 - dictionary comprehension with tuples
03:27 - dictionary comprehension with Pandas Data Frames
03:47 - modify dictionary in place (exercise #1 - superheroes)
08:26 - create a dictionary of lists (exercise #2 - DNA)
14:55 - create a list of dictionaries (exercise #3 - user authentication)
17:23 - create random passwords
20:46 - dictionary and list comprehension disadvantages
21:12 - outro and thanks for watching! :)

💻 Copy starter code 💻
----------------------------------------
⭐ EXERCISE 1:
my_dict = {
"Spider": "photographer",
"Bat": "philanthropist",
"Wonder Wo": "nurse"
}

⭐ EXERCISE 3:
keys = ["id", "username", "password"]
users = ["mariyasha888", "KnotAbot", "spongiBOBO", "IAMBATMAN"]

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💳 Credits 💳
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⭐ Beautiful icons by:
⭐ Beautiful animated graphics by:

[katbryce]

In the DNA example, to simplify the code, I would create a dictionary:
pair = {"A":"T", "C":"G", "G":"C", "T":"A"}
Then, instead of the nested if statements, do
dna = {key:[val, pair[val]] for (key, val) in enumerate(strand1)}

[woled]

The level of polish of the channel in general is really appreciated, thanks for sharing your knowledge !

[victorj.alonzo]

"Let's say that Spiderman is not exactly welcome in this DC dictionary" haha that was funny. I loved the examples.

[GOTHICforLIFE]

I feel like dictionary comprehensions lose a little bit of its readability compared to a conventional loop once you start applying multiple conditions. Especially with group else statements rather than the traditional elif which (as you mentioned) doesn't exists within the comprehension.

But really nice to know about the feature as it never occurred to me that this existed.

[tomislam]

The 'key' to learn dictionary comprehension is to practice this 'value'able exercises in this video.

[josueporrasguajard]

Excellent work! The clarity and didactics with which you have explained each concept are impressive. You have managed to break down complex topics into simple and accessible explanations, which is essential for deep understanding. Your ability to maintain simplicity without losing the essence of the concepts is truly admirable. Keep it up! Congratulations..

[tortugatortuga]

I'm using this to teach a student about dictionaries, thank you!

[sachindeshpande]

First time it was overwhelming for me, but second time it was fun and I could understand it 100%. I need to implement this in real project before I forget it, Thanks a lot.

[davidpimental]

Mariya, you can turn the password generator into a function call. And I also added a UID function as well. Great tutorial though. Thanks so much!

[takeshih.]

My intuition tells me that range approach is faster, because zip approach must contain the procedure to compare between names and profs. Im a newbie for Python programming. Thank you for your videos, that help me a lot to learn Python.

[mikepenprogrammer]

Many thanks for the great content. This should be archived for future data analysts and pythonistas.

[adrianrayon]

lists/dicts comprehension are constantly on that line where they are either great and easy to make and read or just long and ugly and make it harder to read so sometimes they are great, but sometimes it´s just better to do normal for loops

[isojama]

Thank you for this really good video. Definetly the last example was "WOW. I wouldnt be able to do it". Nice !!!!

[greisboy]

If it's just a simple code, go and use list/dict comprehension, but when you logic become more complex, you better write it the old way, it's lot easier to read. Just like lambda for simple function and not for complex function.

[MrDiecrew]

Great video, it is too clear.

A little variation of your code for the exercise #3:

users = ["mariyasha888", "KnotABot", "SpongiBOBO", "IAMBATMAN"]
keys = {
"id": lambda id: id,
"username": lambda username: users[username],
"password": lambda passw: "".join(random.choices(string.printable, k=8))
}
data = [{key:(val(i)) for (key, val) in keys.items()} for i in range(len(users))]

Maybe it's not the best way to do it, but it's just for practice 🙃. I'm learning python 😅. and your videos are very useful!!!

[patricioa]

This was a really good tutorial showing more uses for comprehensions. Thanks!
Also, the addition of the slides showing the important notes was a really good add. That was very welcome.
Thanks again!

[timthompson]

Thanks. Great video! I haven’t used dictionaries much yet, but I’ll come back to this when I do.

[rgAlex]

The most complete tutorial on DC. Can you please sware more on that

[flioink]

I'd expect the "zip" method to be the faster one because it was purpose-made for such cases
and probably has some built-in optimizations, no?
Also the list comprehension where we add "man" works without putting (key, val) in brackets.

[rst]

Requesting for a data structures and algorithm playlist