Introduction to Python
Component of Python
Sets :- A set is a collection of data type that is iterable ,mutable(changeable) ,and has no duplicate elements,and collection is unordered and unindexed. In Python sets are written by curly bracket {}.
Examples:-
Create a set
thisset = {'Banana', 'Mango', 'Apple'}
print(thisset)
So here in above program we had given the command of creating Set data to our Python interpreter. Let’s see .
So our ‘Set’ is been ready.
Here in the Sets data type ,we cannot access item in sets by referring to an index, because sets is unordered the item has no index .
Let’s understand this by an example :-
thisset ={'Banana', 'Mango', 'Apple'}
print(thisset[1])
So here in the above program we just want to access only one item from the sets who is having index no. 1, means ‘Apple’ we want because first one is included ‘0’ in Python.
So let’s see what output it gives :-
It gives the error because it does not support indexing
Changing the items in set is not possible . If a set is been created than you can’t perform any changes into the Sets.
Let’s understand this by an example :-
thisset ={'Banana', 'Mango', 'Apple'}
thisset[2]='Guava'
print(thisset)
So here in the above Program we just gave command to our Python interpreter that we want to change the item , of index number ‘2’ from ‘Mango’ to ‘Guava’ .
So let’s see what output it gives :-
It gives the error because once the Set is created than it can’t change but addition we can do here .
In Sets we can use ‘for’ loop through the specified values present in sets by using the ‘in’ keyword.
Let’s understand this by an example :-
thisset={'Mango' , 'Apple' ,'Banana'}
for X in thisset:
print(X)
So here in the above program we just gave command to our Python interpreter that we want to print all the items , one by one .
So let’s see what output it gives :-
Here it just shows all the elements one by one .
( More about Loops we will talk further on the looping section. )
We can also check items or elements in our sets by using the ‘in’ keyword.
Let us understand this by the following example :-
thisset = {'Banana', 'Mango', 'Apple'}
if 'Mango' in thisset :
print("Yes it is in thisset")
So our ‘Mango’ is in the set . So it just give the correct output.
( We will read in detail regarding ‘if’ statement . )
As we know that methods are basically the function which we want to perform in our coding . In Python there are some inbuilt methods are there for Sets too .
So let’s see some of them :-
The len() method - It just returns the length of the Sets
thisset = (‘Banana’, 'Apple', 'Mango')
print(len(thisset))
So here we just get the length of the set based on their index number.
Adding items on the Set
When you add one item of Set use to add() method.
When you add more than one item to Set use to update() method.
Add an item of sets using add() method
thisset = {'Banana', 'Mango', 'Apple'}
thisset.add('Papaya')
print(thisset))
So here through add() method we add element to our set.
Add multiple Items to a Set, Using the update() method:-
thisset = {'Banana', 'Mango', 'Apple'}
thisset.update(['Papaya','Orange', 'Cherry'])
print(thisset))
So here through update() method we add many elements to our set.
Removing items on sets
For removing the item on Sets, we can use to remove() or discard ()method.
To remove the item of set,using the remove() method .
thisset={'Banana','Mango' , 'Apple'}
thisset.remove('Mango')
print(thisset)
So here it just remove the ‘Mango’ . But if the item remove does not exist ,remove() will rise an the error.
To remove the item of set,using the discard() method .
thisset={'Banana','Mango' , 'Apple'}
thisset.discard('Mango'))
print(thisset)
So here it just remove the ‘Mango’ . But here if the item discard does not exist ,discard() will not rise any error.
The set constructor , set() can used to make a set
thisset = set(('Banana', 'Mango', 'Apple')) # note the double round brackets
print(thisset)
So here through set() constructor our set is ready.
Python has a Set of built-in methods that can use on Sets.
| Method | Description |
|---|---|
| add() | Add element to the set |
| clear() | Remove all the element to the set |
| copy() | Return a copy of the set |
| difference() | Return set containing between two and more sets. |
| difference update()) | Remove the item of Sets and they include other specified |
| discard() | Remove the specified item |
| intersection() | Return a set, and intersection two other sets. |
| intersection update() | Remove the item of this sets that are not present in other specified set() |
| isdisjoint() | Return whether two set intersect or not. |
| issubset() | Check if the Set is Subset of another Set. |
| issuperset() | Check if the Set is Superset of another set |
| pop() | Removes an element from the Set. |
| set() | Return of sets. |
| remove() | Removed the specified element. |
| symmetric difference() | Return Symmetric difference |
| symmetric difference update() | Update Set with Symmetric difference |
| union() | Return a set containing of union set |
| update() | Add element to Set |
| any() | Check if any Element iterable true. |
| all() | Return true when all element iterable is true. |
| ascii() | Return String Containing Printable Representation. |
| bool() | Convert values of boolean. |
| enumerate() | Return the enumerate object. |
| filter() | Construct iterator from element which are true. |
| frozenset() | Return immutable frozenset for object. |
| iter() | Return iterator for an object. |
| max() | Returns largest element. |
| min() | Returns smallest element. |
| len() | Returns length of element. |
| map() | Applies function and returns a list. |
| sorted() | Returns the sorted list given iterable. |
| sum() | Add item to Iterable. |
Check all these methods for good practice.
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