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Programiz
programiz.com › python-programming › set
Python Set (With Examples)
Here, we have used for loop to iterate over a set in Python. We can use the len() method to find the number of elements present in a Set. For example,
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W3Schools
w3schools.com › python › python_sets.asp
Python Sets
Sets are used to store multiple items in a single variable.
Discussions

When should I use a list, dictionary, tuple, or set in Python?
IMO: and this is controversial but will greatly help you organize your data, don't lump tuples in with lists, dictionaries, and sets. A tuple isn't a collection, it's a type. That is, use a tuple when your single object has multiple properties. Like a name or a coordinate. A first and last name together form a name, they don't have much value separately, and the constitute the entirely of the object. In this sense, a tuple of first_name, last_name is a single object, not a collection of separate strings. For example, a CSV file is "best" represented as a list of tuples. Each line is a single thing, but with multiple properties all of which are related. Column 1 and column 2 of a row aren't really a sequence or or collection, but rather feathers on the same chicken (tuple). However, Row 1 and row 2 are related only in that they are the same kind of thing stored together (list). We put the tuples in the list because the parts of the row are more related than the rows of the document. Think about type-hinting a tuple vs a list: a list hint takes exactly one type, and the expectation is that there will be several objects of that type. Conversely, a tuple hint easily accepts multiple types, but needs to know the exact number and position of each type. It's not so much that a tuple is an immutable container, but that a tuple stores an immutable thing. List: Use it when you need to store a lot of the same thing. It's ordered, but it doesn't need to be limited to ordered sequences. That is, a list is generally okay as long as the items don't need to be unordered. A list is good at iterating, but bad at selection, so use it when you will be looping over the items, but not selecting at random. Tuple: A tuple is one thing. You generally don't use it for storage, but for structure. When you have a thing with multiple parts, that's a tuple. When you have multiple things, that's a list. Unlike a list, a tuple is very likely to contain different types, while a list is (should) contain elements of a single type. Again, a tuple is good at iteration and bad at selection. A dictionary and set are really close to the same thing--they are hashes. Hashes are bad at iteration, but good at selection, so they are best when you need to select items from the container at random--not in order. They are semi-ordered, meaning you can now expect the order to remain, but if you need items to be in order it's probably not the right type. If you need a key->value relationship, then you want a dict, otherwise, you want a set. Use lists when order matters and you need to modify elements. Order doesn't need to matter, it just needs to be inconsequential. Also, avoid the "modify" criteria as almost all "real" collections are modifiable. Lists end up being sort of a "default", so without a reason to choose something else, or a reason to avoid a list, most of the time a list is fine. Use tuples when you need an immutable sequence (e.g., function return values). Again, look at this as a single object. Use tuples when you are returning a complex single object, not a sequence. You can return a list from a function just as easily as a tuple, so I don't consider return values a good selection criteria. However, your function should be returning "one thing", so in that sense a tuple makes sense, but from the other direction. Use sets when you need fast lookups and uniqueness. Use dictionaries when mapping keys to values efficiently. again, I would avoid thinking about sets and dictionaries as a top-level division. Instead, think "do I need a hash", and then "do I need key->value pairs" to choose between them. Is this not actually a collection of separate, but similar, objects? Then you want a tuple, or something more sophisticated like a NamedTuple, DataClass, or Class Is this a sequence? That is, do you need these items in order, or don't care about which one you get next, or will be dealing with all the items at once (even if one-by-one)? This is a list. Is this more of a "soup"? Where you want a specific item next, and don't care about order, or will be dealing with only specific objects at once? More on reddit.com
🌐 r/learnpython
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100
March 6, 2025
How to set system prompt in ollama
You can either set it using ollama cli ollama run llama2-uncensored >>> /set system "blah-blah-blah" Or just create a Modelfile like this FROM llama2-uncensored SYSTEM "blah-blah-blah" And then create new model ollama create llama2:blah -f Modelfile Please note that not all models accept system prompts. It should work fine on llama2, but for example, solus don't understand system prompt. Personally, I would be using ChatBox as UI for that because ChatBox allows to adjust system prompts with ease using copilot functionality. More on reddit.com
🌐 r/ollama
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18
May 24, 2024
Found a bug in Python 3.7's dataclass.asdict()

I would be so excited to find a real bug.

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🌐 r/Python
38
200
September 8, 2018
Python and reading registry keys.
https://docs.python.org/3.4/library/winreg.html More on reddit.com
🌐 r/learnpython
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3
February 5, 2015
People also ask

What are set operations in Python?
Python sets support operations like union, intersection, difference, and symmetric difference, helping you compare, merge, or filter sets easily.
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wscubetech.com
wscubetech.com › resources › python › sets
Set in Python: All Methods With Examples
How do I define a set in Python?
You can define a set using curly braces {} like my_set = {1, 2, 3} or use set() to create one from a list or string. Both ways store unique items only.
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wscubetech.com
wscubetech.com › resources › python › sets
Set in Python: All Methods With Examples
What is a set in Python and why should I use it?
A set in Python is a collection of unique items with no duplicates allowed. You should use it when you want to store non-repeating data like tags, IDs, or filtered results.
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wscubetech.com
wscubetech.com › resources › python › sets
Set in Python: All Methods With Examples
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GeeksforGeeks
geeksforgeeks.org › python › sets-in-python
Python Sets - GeeksforGeeks
Set is a built-in Python data type used to store a collection of unique items. Stores only unique elements; duplicate values are automatically removed. Unordered collection, so elements do not have a fixed position and cannot be accessed using indexes. Supports fast search, insertion and deletion operations using hashing internally. Example: This example shows how to create a set with some numbers and check its type.
Published: August 11, 2026
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freeCodeCamp
freecodecamp.org › news › python-set-operations-explained-with-examples
Python Sets – Operations and Examples
April 23, 2025 - So, when we tried to add "cello" again to the set, Python recognized we were trying to add a duplicate element and didn't update the set. This is one caveat that differentiates sets from lists. ... The remove(x) function removes the element x from a set. It returns a KeyError if x is not part of the set: >>> sub_set.remove("guitar") Traceback (most recent call last): File "<stdin>", line 1, in <module> KeyError: 'guitar'
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Real Python
realpython.com › python-sets
Sets in Python – Real Python
May 5, 2025 - In this example, you pass a list of numbers to set(). Note how the originally duplicate values are only represented once in the resulting set. Python strings are also iterable, so you can pass a string to set().
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W3Schools
w3schools.com › python › ref_func_set.asp
Python set() Function
Python Overview Python Built-in ... Python Set Methods Python File Methods Python Keywords Python Exceptions Python Glossary · Built-in Modules Random Module Requests Module Statistics Module Math Module cMath Module · Remove List Duplicates Reverse a String Add Two Numbers · Python Examples Python Compiler ...
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LearnPython.com
learnpython.com › blog › python-set-example
Python Set Examples: From Basic to Advanced Use Cases | LearnPython.com
November 20, 2023 - As a mutable data structure, a Python set can dynamically change the elements it contains. This behavior is on par with most other data structures in Python, such as lists and dictionaries. In the example below, we start with an empty set and sequentially put new elements in it using the .add() method:
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WsCube Tech
wscubetech.com › resources › python › sets
Set in Python: All Methods With Examples
August 6, 2026 - Learn about Python sets with easy examples and output. Understand how to create sets, add and remove items, and practice your skills with a quiz.
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GeeksforGeeks
geeksforgeeks.org › python › python-set-function
set() Function in python - GeeksforGeeks
February 17, 2026 - It removes duplicate values automatically and accepts an iterable such as a list, tuple, string, range or dictionary. Example: In this example, set() is used to create a set from a list containing duplicate values.
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freeCodeCamp
freecodecamp.org › news › how-to-use-sets-in-python
How to Use Sets in Python – Explained with Examples
March 4, 2024 - Imagine you're hosting a gathering of friends from diverse backgrounds, each with their unique identity. Now, picture this gathering as a set – a collection where each individual is distinct, much like the elements of a set in Python.
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Python Tutorial
pythontutorial.net › home › python basics › python set
A Basic Guide to the Python Set By Practical Examples
October 17, 2020 - Since a set is an iterable, you can use a for loop to iterate over its elements. For example: skills = {'Problem solving', 'Software design', 'Python programming'} for skill in skills: print(skill) Copy
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Hyperskill
hyperskill.org › university › python › set-and-set-in-python
Python set(): Create Sets, Add, Remove & Compare Elements
June 5, 2026 - In Python, a set is a built-in data structure used to store a collection of unique items. It is mutable, meaning its elements can be modified, added, or removed.
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GeeksforGeeks
geeksforgeeks.org › sets-in-python
Sets in Python - GeeksforGeeks
We are given a set and our task is to find its length. For example, if we have a = {1, 2, 3, 4, 5}, the length of the set should be 5.Using len()len() function in Python returns the number of elements in a set.
Published: February 4, 2025
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BrainStation®
brainstation.io › learn › python › set
Python Set (2026 Tutorial & Examples) | BrainStation®
February 4, 2025 - Let’s dive into the Python set and understand how to use them as a data type. Below is an example that creates two sets as a wishlist of movies to watch for two different people. Sets are created using curly brackets.
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Programiz
programiz.com › python-programming › methods › built-in › set
Python set()
iterable (optional) - a sequence (string, tuple, etc.) or collection (set, dictionary, etc.) or an iterator object to be converted into a set. ... print(set('Python')) # from tuple print(set(('a', 'e', 'i', 'o', 'u'))) # from list print(set(['a', 'e', 'i', 'o', 'u'])) # from range
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Learn By Example
learnbyexample.org › python-set
Python Set - Learn By Example
May 3, 2020 - Python set is an unordered collection of unique items. They are commonly used for computing mathematical operations such as union, intersection, difference, and symmetric difference.
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Great Learning
mygreatlearning.com › blog › it/software development › set in python – how to create a set in python?
Set in Python – How to Create a Set in Python?
October 14, 2024 - You can create an empty set in python by using the set() function. One can think an empty set can be created using the curly braces {}, but notice that python interprets empty curly braces as a dictionary. Let us look at this scenario using an example:
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Codecademy
codecademy.com › docs › python › sets
Python | Sets | Codecademy
April 16, 2025 - In the example below, sets are created with lists and the set() function.
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InterServer
interserver.net › home › python › python sets explained with examples: create, use, and avoid mistakes
Python Sets Explained with Examples: Create, Use, and Avoid Mistakes - Interserver Tips
April 23, 2026 - There are a few simple ways to create sets in Python. Let’s go through them one by one. The easiest way to create a set is by using curly braces {} and separating items with commas. Here’s a quick example: