Python: Constructor Set()

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I was looking at the python documentation about set(), but I'm still trying to understand why does this function deletes repeated characters in a string, for example:

set("apple")

returns {"a","p","l","e"}. Is it a special property of sets?


Per the first sentence of the set docs (emphasis added):

A set object is an unordered collection of distinct hashable objects.

"distinct" can be interpreted here to mean "unique" or "non-repeating" objects; as the example use cases note:

Common uses include membership testing, removing duplicates from a sequence, and computing mathematical operations such as intersection, union, difference, and symmetric difference.

Because str are iterables of their own letters, set("apple") is essentially a faster equivalent to set(["a", "p", "p", "l", "e"]), which causes the duplicated letters to be removed. If you'd wanted a set with an initial entry of "apple", you'd use {"apple"} (set literal) or set(("apple",))/set(["apple"]) (set constructor applied to tuple or list of values to include). This is a general property of str, not specific to set cases; list("apple") would produce ["a", "p", "p", "l", "e"] for the same reason.

Python set(), Python set()​​ set() takes a single optional parameter: iterable (optional) - a sequence (string, tuple, etc.) or collection (set, dictionary, etc.) or an iterator object to be converted into a set. You can either use a list of numbers to initialize a set, like this. set([150, 75, 23, 86, 49]) Or you can use set literal notation, like this {150, 75, 23, 86, 49} The advantage of the set constructor is that, we can use any iterator which has hashble items in it.


Yes sets contain unique elements and are much faster for comparisons like checking if an item exists than lists for example. As well as having lots of other nice properties.

so another example would be

set([1,1,1,2,3])

returns

{1,2,3}

the unique items.

One thing to note is that sets are not ordered like lists, which has both positives and negatives

Python set() constructor, Closed 5 years ago. How to modify the Set() constructor to accept an optional variable argument to which a collection of initial values can be  Python set() The set() constructor constructs a Python set from the given iterable and returns it. The syntax of set() constructor is:


set() accepts an iterable in this case apple is treated as one, yielding 'a', 'p', 'p', 'l', 'e' which are then added to the set and because sets only contain unique elements you end up with {"a","p","l","e"}.

Python Constructors - default and parameterized, Python Constructors – default and parameterized. By Chaitanya This invokes constructor obj = DemoClass() # calling the instance method using the object obj​  Constructors are generally used for instantiating an object.The task of constructors is to initialize (assign values) to the data members of the class when an object of class is created.In Python the __init__ () method is called the constructor and is always called when an object is created.


If an optional iterable parameter is supplied to set(), it updates the set with elements obtained from iteration. That is from the docs.

set('apple')
{'a', 'p', 'l', 'e'}
set(('a','p','p','l','e'))
{'a', 'p', 'l', 'e'}
set(['a','p','p','l','e'])
{'a', 'p', 'l', 'e'}

A set only contains unique elements. When you pass it an iterable, ie. string, tuple, list - It creates a set, iterating over the passed in object.

Python Constructors, to perform tasks such as initializing (assigning values to) any instance variables that the object will need when it starts. The constructor is a method that is called when an object is created. This method is defined in the class and can be used to initialize basic variables. If you create four objects, the class constructor is called four times. Every class has a constructor, but its not required to explicitly define it.


Python, Being an unordered collection, sets do not record element position or order of insertion. so all of the elements must be known when the constructor is called. s ^ t. new set with elements in either s or t but not both. s.copy(). A constructor is a special kind of method which is used for initializing the instance variables during object creation. In this guide, we will see what is a constructor, types of it and how to use them in the python programming with examples.


How to Create a Constructor in Python, If no index is specified, a.pop() removes and returns the last item in the list. (The square Curly braces or the set() function can be used to create sets. The dict​() constructor builds dictionaries directly from sequences of key-value pairs: >>> A constructor is a special kind of method that Python calls when it instantiates an object using the definitions found in your class. Python relies on the constructor to perform tasks such as initializing (assigning values to) any instance variables that the object will need when it starts. Constructors can also verify that there are enough resources for the object and perform any other start-up task you can think of.


What are constructors in Python?, A constructor is a special kind of method that Python calls when it instantiates an object using the definitions found in It sets Greeting to the value of this name, plus an exclamation mark. 3Type MyInstance = MyClass() and press Enter. Python Constructor A constructor is a special type of method (function) which is used to initialize the instance members of the class. Constructors can be of two types.