Set methods in python

  1. 3. Data model — Python 3.11.4 documentation
  2. Python Set Methods
  3. Understanding __get__ and __set__ and Python descriptors
  4. Python Set
  5. Python Set (With Examples)


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3. Data model — Python 3.11.4 documentation

3. Data model 3.1. Objects, values and types Objects are Python’s abstraction for data. All data in a Python program is represented by objects or by relations between objects. (In a sense, and in conformance to Von Neumann’s model of a “stored program computer”, code is also represented by objects.) Every object has an identity, a type and a value. An object’s identity never changes once it has been created; you may think of it as the object’s address in memory. The ‘ is’ operator compares the identity of two objects; the id() function returns an integer representing its identity. CPython implementation detail: For CPython, id(x) is the memory address where x is stored. An object’s type determines the operations that the object supports (e.g., “does it have a length?”) and also defines the possible values for objects of that type. The type() function returns an object’s type (which is an object itself). Like its identity, an object’s type is also unchangeable. The value of some objects can change. Objects whose value can change are said to be mutable; objects whose value is unchangeable once they are created are called immutable. (The value of an immutable container object that contains a reference to a mutable object can change when the latter’s value is changed; however the container is still considered immutable, because the collection of objects it contains cannot be changed. So, immutability is not strictly the same as having an unchangeable value, it is more subtle.)...

Python Set Methods

Fruits_set = type(Veggie_set) Veggie_set.add("Lady-finger") print(Veggie_set) Output: As one sees “Veggie_set.add(“Lady-finger”)” this helps in adding the element “Lady-finger” in the list name “Veggie_Set”. 3. clear() This method helps in clearing the set. No element remains in the set after this method is applied. Code: Veggie_set = print(Veggie_set2) New_set = Veggie_set1.intersection(Veggie_set2) print(New_set) Output: As one can notice, how the common elements are taken out by the function intersection(). Common elements printed are “Cabbage” and “Cauliflower”, which returned in the form of a set. If one has to take an intersection between more than one set, this is how it can be done: Code: Veggie_set1 = print(Veggie_set2) check1 = Veggie_set1.issuperset(Veggie_set2) print(check1) check2 = Veggie_set2.issuperset(Veggie_set1) print(check2) Output: As one can notice, all elements of “Veggie_set1” are part of “Veggie_set2”. That means “Veggie_set2” is a superset of “Veggie_set1” Hence: Statement “Veggie_set1.issuperset(Veggie_set2)” returns False. Statement “Veggie_set2.issuperset(Veggie_set1)” returns True. 9. symmetric_difference() This method helps you find the elements that are part of sets but not common to both sets. Code: Veggie_set1 = print(Veggie_set2) Veggie_set2.update(Veggie_set1) print(Veggie_set2) Output: One can see, “Kale” which was part of “Veggie_set1”. But after performing update() over “Veggie_set2” with “Veggie_set1”, “Kale” became an element of...

Understanding __get__ and __set__ and Python descriptors

I am trying to understand what Python's descriptors are and what they are useful for. I understand how they work, but here are my doubts. Consider the following code: class Celsius(object): def __init__(self, value=0.0): self.value = float(value) def __get__(self, instance, owner): return self.value def __set__(self, instance, value): self.value = float(value) class Temperature(object): celsius = Celsius() • Why do I need the descriptor class? • What is instance and owner here? (in __get__). What is the purpose of these parameters? • How would I call/use this example? The descriptor is how Python's property type is implemented. A descriptor simply implements __get__, __set__, etc. and is then added to another class in its definition (as you did above with the Temperature class). For example: temp=Temperature() temp.celsius #calls celsius.__get__ Accessing the property you assigned the descriptor to ( celsius in the above example) calls the appropriate descriptor method. instance in __get__ is the instance of the class (so above, __get__ would receive temp, while owner is the class with the descriptor (so it would be Temperature). You need to use a descriptor class to encapsulate the logic that powers it. That way, if the descriptor is used to cache some expensive operation (for example), it could store the value on itself and not its class. The official Python documentation includes an EDIT: As jchl pointed out in the comments, if you simply try Temperature.celsius, instan...

Python Set

You can use sets in Python to store a collection of data in a single variable. Each of the built-in data structures in Python like lists, dictionaries, and tuples have their distinguishing features. Here are some of the features of sets in Python: • Duplicate items are not allowed. If items appear multiple times, only one will be recognized in the set. • The items in a set are unordered. The order of the set changes every time it is used. • The value of items in a set cannot be modified/changed once the set has been created. In this article, you'll learn how to create sets. You'll also learn how to access, add, and remove items in a set in Python. We'll conclude by talking about some of the use cases of sets in Python programming and mathematics. How to Create Sets in Python We use curly brackets to store the items in a set. Here's what a set looks like: nameSet = We used the ^ operator to get the symmetric difference of two sets: firstSet ^ secondSet. The result was 1, 2, 4, 7. Each of these items do not appear in both sets. Summary In this article, we talked about sets and how to create them in Python. Sets do not allow duplicate items, they are unordered, and the items stored in them cannot be modified. We also saw how to access, add, and remove items in sets using different methods. Lastly, we talked about when to use sets in Python. We saw some of the applications of sets in Python and its use in mathematical operations. Happy coding!

Python Set (With Examples)

A set is a collection of unique data. That is, elements of a set cannot be duplicate. For example, Suppose we want to store information about student IDs. Since student IDs cannot be duplicate, we can use a set. Python Set Elements Create a Set in Python In Python, we create sets by placing all the elements inside curly braces Finally we have used the type() function to know which class empty_set and empty_dictionary belong to. Duplicate Items in a Set Let's see what will happen if we try to include duplicate items in a set. numbers = Here, we have used the discard() method to remove 'Java' from the languages set. Built-in Functions with Set Built-in functions like all(), any(), enumerate(), len(), max(), min(), sorted(), sum() etc. are commonly used with sets to perform different tasks. Function Description Returns True if all elements of the set are true (or if the set is empty). Returns True if any element of the set is true. If the set is empty, returns False. Returns an enumerate object. It contains the index and value for all the items of the set as a pair. Returns the length (the number of items) in the set. Returns the largest item in the set. Returns the smallest item in the set. Returns a new sorted list from elements in the set(does not sort the set itself). Returns the sum of all elements in the set. Iterate Over a Set in Python fruits = # perform difference operation using & if A == B: print('Set A and Set B are equal') else: print('Set A and Set B are not ...