Sets in Pyhton
Sets in Pyhton
In python, a set is another type of collection data type. A Set is a mutable and an unordered collection of elements without duplicates. That means the elements within a set cannot be repeated. This feature used to include membership testing and eliminating duplicate elements.
Creating a Set
A set is created by placing all the elements separated by comma within a pair of curly brackets. The set( ) function can also used to create sets in Python.
Syntax:
Set_Variable = {E1, E2, E3 …….. En}Example
>>> S1={1,2,3,'A',3.14}
>>> print(S1)
{1, 2, 3, 3.14, 'A'}
>>> S2={1,2,2,'A',3.14}
>>> print(S2)
{1, 2, 'A', 3.14}
In the above examples, the set S1 is created with different types of elements without duplicate values. Whereas in the set S2 is created with duplicate values, but python accepts only one element among the duplications. Which means python removed the duplicate value, because a set in python cannot have duplicate elements.
Creating Set using List or Tuple
A list or Tuple can be converted as set by using set( ) function. This is very simple procedure. First you have to create a list or Tuple then, substitute its variable within set( ) function as argument.
Example
MyList=[2,4,6,8,10]
MySet=set(MyList)
print(MySet)
Output:
{2, 4, 6, 8, 10}
Set Operations
As you learnt in mathematics, the python is also supports the set operations such as Union, Intersection, difference and Symmetric difference.
Union: It includes all elements from two or more sets
Positive Numbers: (5, 6, 8, 3, 1)
In python, the operator | is used to union of two sets. The function union( ) is also used to join two sets in python.
Example: Program to Join (Union) two sets using union operator
set_A={2,4,6,8}
set_B={'A', 'B', 'C', 'D'}
U_set=set_A|set_B
print(U_set)
Output:
{2, 4, 6, 8, 'A', 'D', 'C', 'B'}
Example: Program to Join (Union) two sets using union function
set_A={2,4,6,8}
set_B={'A', 'B', 'C', 'D'}
set_U=set_A.
print(set_U)Output:
{'D', 2, 4, 6, 8, 'B', 'C', 'A'}
(ii) Intersection: It includes the common elements in two sets
Th e operator & is used to intersect two sets in python. Th e function intersection( ) is also used to intersect two sets in python.
Example: Program to insect two sets using intersection operator
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A & set_B)
Output:
{'A', 'D'}
Example: Program to insect two sets using intersection function
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A.intersection(set_B))
Output:
{'A', 'D'}
(iii) Difference : It includes all elements that are in fi rst set (say set A) but not in the second set (say set B)
Th e minus (-) operator is used to diff erence set operation in python. Th e function difference( ) is also used to diff erence operation.
Example: Program to difference of two sets using minus operator
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A - set_B)
Output:
{2, 4}
Example: Program to difference of two sets using difference function
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A.diff erence(set_B))
Output:
{2, 4}
(iv) Symmetric difference : It includes all the elements that are in two sets (say sets A and B) but not the one that are common to two sets.
The caret (^) operator is used to symmetric difference set operation in python. The function symmetric_difference( ) is also used to do the same operation.
Example: Program to symmetric difference of two sets using caret operator
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A ^ set_B)
Output:
{2, 4, 'B', 'C'}
Example: Program to difference of two sets using symmetric difference function
set_A={'A', 2, 4, 'D'}
set_B={'A', 'B', 'C', 'D'}
print(set_A.symmetric_difference(set_B))
Output:
{2, 4, 'B', 'C'}
Qus. 1 : <p>What will be the output of the following Python code?</p><pre>d = {0, 1, 2}<br>for x in d:<br> print(d.add(x))</pre>
- 0 1 2
- 0 1 2 0 1 2 0 1 2 …
- None None None
- None of the mentioned
- Mutable data type
- Allows duplicate values
- Data type with unordered values
- Immutable data type
- { }
- set()
- [ ]
- ( )
What will be the output of the following Python code?
>>> a={5,4} >>> b={1,2,4,5} >>> a<b
- {1,2}
- True
- False
- Invalid operation
- print(len(a))
- print(min(a))
- a.remove(5)
- a[2]=45
- a={5,5,6,7}
- a={5,6,7}
- Error as there is no add function for set data type
- Error as 5 already exists in the set
What will be the output of the following Python code?
>>> a={4,5,6} >>> b={2,8,6} >>> a+b
- {4,5,6,2,8}
- {4,5,6,2,8,6}
- Error as unsupported operand type for sets
- Error as the duplicate item 6 is present in both sets
What will be the output of the following Python code?
>>> a={4,5,6} >>> b={2,8,6} >>> a-b
- {4,5}
- {6}
- Error as unsupported operand type for set data type
- Error as the duplicate item 6 is present in both sets
What will be the output of the following Python code?
>>> a={5,6,7,8} >>> b={7,8,10,11} >>> a^b
- {5,6,7,8,10,11}
- {7,8}
- Error as unsupported operand type of set data type
- {5,6,10,11}
What will be the output of the following Python code?
>>> s={5,6} >>> s*3
- Error as unsupported operand type for set data type
- {5,6,5,6,5,6}
- {5,6}
- Error as multiplication creates duplicate elements which isn’t allowed
What will be the output of the following Python code?
>>> a={3,4,5} >>> b={5,6,7} >>> a|b
- Invalid operation
- {3, 4, 5, 6, 7}
- {5}
- {3,4,6,7}
- Yes, 7 is printed
- Error, elements of a set can’t be printed
- Error, subsets aren’t allowed
- Yes, {7,5} is printed
- Mutable data type
- Allows duplicate values
- Data type with unordered values
- Immutable data type
Is the following Python code valid?
>>> a=frozenset([5,6,7])
>>> a >>> a.add(5)
- Yes, now is a {5,5,6,7}
- No, frozen set is immutable
- No, invalid syntax for add method
- Yes, now a is {5,6,7}
What will be the output of the following Python code?
>>> a={3,4,5}
>>> a.update([1,2,3])
>>> a
- Error, no method called update for set data type
- {1, 2, 3, 4, 5}
- Error, list can’t be added to set
- Error, duplicate item present in list
What will be the output of the following Python code?
>>> a={1,2,3}
>>> a.intersection_update({2,3,4,5})
>>> a
- {2,3}
- Error, duplicate item present in list
- Error, no method called intersection_update for set data type
- {1,4,5}
What will be the output of the following Python code?
>>> a={1,2,3}
>>> b=a >>> b.remove(3)
>>> a
- {1,2,3}
- Error, copying of sets isn’t allowed
- {1,2}
- Error, invalid syntax for remove
What will be the output of the following Python code?
>>> a={1,2,3}
>>> b=a.copy() >>> b.add(4)
>>> a
- {1,2,3}
- Error, invalid syntax for add
- {1,2,3,4}
- Error, copying of sets isn’t allowed
What will be the output of the following Python code?
>>> a={1,2,3}
>>> b=a.add(4)
>>> b
- None
- {1,2,3,4}
- {1,2,3}
- Nothing is printed
What will be the output of the following Python code?
>>> a={1,2,3}
>>> b=frozenset([3,4,5])
>>> a-b
- {1,2}
- Error as difference between a set and frozenset can’t be found out
- Error as unsupported operand type for set data type
- frozenset({1,2})
- 5
- 23
- 18
- Invalid syntax for sum method, too many arguments
What will be the output of the following Python code?
>>> a={1,2,3}
>>> {x*2 for x in a|{4,5}}
- {2,4,6}
- Error, set comprehensions aren’t allowed
- {8, 2, 10, 4, 6}
- {8,10}
What will be the output of the following Python code?
>>> a={5,6,7,8}
>>> b={7,8,9,10}
>>> len(a+b)
- 8
- Error, unsupported operand ‘+’ for sets
- 6
- Nothing is displayed
Is the following Python code valid?
a={1,2,3}
b={1,2,3,4}
c=a.issuperset(b)
print(c)
- False
- True
- Syntax error for issuperset() method
- Error, no method called issuperset() exists
What will be the output of the following Python code?
s=set()
type(s)
- <’set’>
- <class ‘set’>
- set
- class set
- keys, keys
- key values, keys
- keys, key values
- key values, key values
- s={abs}
- s={4, ‘abc’, (1,2)}
- s={2, 2.2, 3, ‘xyz’}
- s={san}
What will be the output of the following Python code?
s={2, 5, 6, 6, 7}
s
- {2, 5, 7}
- {2, 5, 6, 7}
- {2, 5, 6, 6, 7}
- Error
Write a list comprehension for number and its cube for:
l=[1, 2, 3, 4, 5, 6, 7, 8, 9]
- [x**3 for x in l]
- [x^3 for x in l]
- [x**3 in l]
- [x^3 in l]
What will be the output of the following Python code?
s={1, 2, 3}
s.update(4)
s
- {1, 2, 3, 4}
- {1, 2, 4, 3}
- {4, 1, 2, 3}
- Error
- pop
- remove
- update
- sum
What will be the output of the following Python code?
s={4>3, 0, 3-3}
all(s)
any(s)
- True False
- False True
- True True
- False False
- x | y
- x ^ y
- x & y
- x – y
What will be the output of the following Python code snippet?
z=set('abc$de') 'a' in z
- True
- False
- No output
- Error
What will be the output of the following Python code snippet?
z=set('abc')
z.add('san') z.update(set(['p', 'q']))
z
- {‘abc’, ‘p’, ‘q’, ‘san’}
- {‘a’, ‘b’, ‘c’, [‘p’, ‘q’], ‘san}
- {‘a’, ‘c’, ‘c’, ‘p’, ‘q’, ‘s’, ‘a’, ‘n’}
- {‘a’, ‘b’, ‘c’, ‘p’, ‘q’, ‘san’}
What will be the output of the following Python code snippet?
{a**2 for a in range(4)}
- {1, 4, 9, 16}
- {0, 1, 4, 9, 16}
- Error
- {0, 1, 4, 9}
. What will be the output of the following Python code?
s1={3, 4}
s2={1, 2} s3=set() i=0 j=0 for i in s1: for j in s2: s3.add((i,j)) i+=1 j+=1
print(s3)
- {(3, 4), (1, 2)}
- Error
- {(4, 2), (3, 1), (4, 1), (5, 2)}
- {(3, 1), (4, 2)}
- remove
- pop
- discard
- dispose
- s2.issubset(s1)
- s2.issuperset(s1)
- s1.issuperset(s2)
- s1.isset(s2)
What will be the output of the following Python code, if s1= {1, 2, 3}?
s1.issubset(s1)
- True
- Error
- No output
- False
- {‘d’, ‘c’, ‘m’, ‘l’, ‘p’, ‘c’}
- {‘m’, ‘l’, ‘p’, ‘c’}
- {‘d’, ‘c’, ‘m’, ‘a’}
- None of These
- set
- tuple
- string
- None of These
Programs
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python program to display the maximum elements from the two list along with its index in its list
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python program to interchange the values of two tuple
python program to interchange the values of two tuple
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python program that reverse the list of integers in place
python program to input two list and create third list which contains all elements of the first elements followed by all elements of second list
python program to inter list of string and create a new list that consist of those strings with their first characters removed
python program to create a list using for loop which consist of integers 0 through 49
python program to create a list using for loop which consist square of the integers 1 through 50
python program to create a list using for loop which consist a bb ccc dddd that ends with 26 copies of the letter z.
python program that takes any two list L and M of the same size and adds their elements together in another third list
python program to rotates the elements of list so that fist elements move to second and second to the third
python program to move all duplicate element to the end of list
python program to display the maximum and minimum values form specified range of indexes of a list
python program to compare two equal sized list and print the first index where they differ
python program to enter names of employees and their salaries as input and store them in a dictionary
python program to count the number of times a character appears in a given string
python program to convert a number entered by the user into its corresponding number in words
python program Repeatedly ask the user to enter a team name
python program that repeatedly asks the user to enter product names and prices
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python program to Create a dictionary with the opposite mapping
python program that lists the over lapping keys of the two dictionaries if a key of d1 is also a key of d2 the list it
python program that checks if two same values in a dictionary have different keys
python program to check if a dictionary is contained in another dictionary
python program to create a new dictionary D2 having same keys as D1 but values as the sum of the list elements
python program to create a dictionary has three keys assets liabilities and capital
python program that create a tuple storing first 9 terms of Fibonacci series
python program that receives the index and return the corresponding value
Python program that receives a Fibonacci series term and returns a number telling which term it is
python program to create a nested tuple to store roll number name and marks of students
python program that interactively creates a nested tuple to store the marks in three subjects for five students
Python Program to accept three distinct digits and print all possible combinations from the digits
Python Program to find the successor and predecessor of the largest element in list
Python function that takes a string as parameter and returns a string with every successive repetitive character replaced