Python update() function in set adds elements from a set (passed as an argument) to the set.
Syntax : set1.update(set2)
Here set1 is the set in which set2 will be added.
Parameters : Update() method takes any number of argument. The arguments can be a set, list, tuples or a dictionary. It automatically converts into a set and adds to the set.
Return value : This method adds set2 to set1 and returns nothing.
Example of Python set update()
Example 1: Working with Python set update list
Python3
# Python program to demonstrate the # use of update() method list1 = [ 1 , 2 , 3 ] list2 = [ 5 , 6 , 7 ] list3 = [ 10 , 11 , 12 ] # Lists converted to sets set1 = set (list2) set2 = set (list1) # Update method set1.update(set2) # Print the updated set print (set1) # List is passed as an parameter which # gets automatically converted to a set set1.update(list3) print (set1) |
Output :
{1, 2, 3, 5, 6, 7} {1, 2, 3, 5, 6, 7, 10, 11, 12}
Example 2: Python set update element in set
Python3
# Python program to demonstrate the # use of update() method list1 = [ 1 , 2 , 3 , 4 ] list2 = [ 1 , 4 , 2 , 3 , 5 ] alphabet_set = { 'a' , 'b' , 'c' } # lists converted to sets set1 = set (list2) set2 = set (list1) # Update method set1.update(set2) # Print the updated set print (set1) set1.update(alphabet_set) print (set1) |
Output :
{1, 2, 3, 4, 5} {1, 2, 3, 4, 5, 'c', 'b', 'a'}
Example 3: Add elements of the dictionary to Set
Python3
number = { 1 , 2 , 3 , 4 , 5 } num_Dict = { 6 : 'Six' , 7 : 'Seven' , 8 : 'Eight' , 9 : 'Nine' , 10 : 'Ten' } number.update(num_Dict) print ( "Updated set: " , number) |
Output:
Updated set: {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}