Sets In Python

-

 

# with no duplicate elements.
# Basic uses include membership testing
# and eliminating duplicate entries.
# Set objects also support mathematical operations
# like union, intersection, difference,
# and symmetric difference.

s = set()
print(type(s)) # Output : <class 'set'>

l = [1, 2, 3, 4]
s_from_list = set(l)
print(s_from_list)
# Output : {1, 2, 3, 4}
print(type(s_from_list))
# Output : <class 'set'>

s.add(1) # 1 will be added to empty set s
print(s) # Output : {1}

s.add(1) # Nothing change as set stores unique items
print(s) # Output : {1}

s.add(2)
print(s) # Output : {1, 2}

s.remove(2) # Remove 2 from set
print(s) # Output : {1}

# Union of set s and {1, 2, 3}
s1 = s.union({1, 2, 3})
print(s, s1) # Output : {1} {1, 2, 3}

# Intersection of set s and {1, 2, 3}
s1 = s.intersection({1, 2, 3})
print(s, s1) # Output : {1} {1}

s = {1, 4, 5, 6, 6}
print(len(s)) # Output : 4
print(max(s)) # Output : 6
print(min(s)) # Output : 1

s = {1, 2}
s1 = {4, 6}
print(s.isdisjoint(s1)) # Output : True

############# Extra Content #######################

# >>> # Demonstrate set operations on unique letters from two words
# ...
# >>> a = set('abracadabra')
# >>> b = set('alacazam')
# >>> a # unique letters in a
# {'a', 'r', 'b', 'c', 'd'}
# >>> a - b # letters in a but not in b
# {'r', 'd', 'b'}
# >>> a | b # letters in a or b or both
# {'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'}
# >>> a & b # letters in both a and b
# {'a', 'c'}
# >>> a ^ b # letters in a or b but not both
# {'r', 'd', 'b', 'm', 'z', 'l'}

# set comprehensions are also supported:

# >>>
# >>> a = {x for x in 'abracadabra' if x not in 'abc'}
# >>> a
# {'r', 'd'}
# A set is an unordered collection

Comments

Post a Comment

Popular posts from this blog

MAP FILTER AND REDUCE FUNCTION IN PYTHON

-
  numbers = [ "3" , "34" , "64" ] numbers = list ( map ( int , numbers)) for i in range ( len (numbers)): numbers[i] = int (numbers[i]) numbers[ 2 ] = numbers[ 2 ] + 1 print (numbers[ 2 ]) def sq (a): return a*a num =[ 2 , 5 , 6 , 7 , 9 , 6 , 4 , 3 ] square = list ( map (sq, num)) print (square) num =[ 2 , 5 , 6 , 7 , 9 , 6 , 4 , 3 ] square = list ( map ( lambda x: x*x, num)) print (square) def square (a): return a*a def cube (a): return a*a*a func = [square,cube] for i in range ( 6 ): val = list ( map ( lambda x:x(i), func)) print (val) ################################### FILTER #################################### list_1 = [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ] def is_greater_4 (num): return num> 4 gr_than_5 = list ( filter (is_greater_4, list_1)) print (gr_than_5) ################################### REDUCE ################################# from functools import reduce list1 = [ 1 , 2 , 3 , 4 , 5 ] num = reduce( lambda x,y:x...
Read more

Writing Appending to a File

-
# f is better to say file handle which open() return # instead saying it pointer but commonly f also known as file pointer # Opening file in write,text mode # Only 'w' mentioned below because t-text mode is by default # So 'w' is same as 'wt' # IF file "26. Tutorial.txt" not exist then it will create that. # If alrady exist then it will replace all the content with what we will write in the file # f = open("26. Tutorial1.txt", "w") # f.write("Rural Development Party - A party that contests only gram panchayat elections and has the vision to make World Class Villages with limited resources.\n") # f.close() # If we again do f.write on same file it just replace content # but in most cases we want to append the content in the file at end # for that open file in append mode -'a' # f = open("26. Tutorial1.txt", "a") # due to newline character "\n" at the last of previous write # this content...
Read more

Recursions: Recursive Vs Iterative Approach

-
# n! = n * n-1 * n-2 * n-3.......1 # n! = n * (n-1)! def factorial_iterative (n): """ :param n: Integer :return: n * n-1 * n-2 * n-3.......1 """ fac = 1 for i in range (n): fac = fac * (i + 1 ) return fac # def factorial_recursive (n): """ :param n: Integer :return: n * n-1 * n-2 * n-3.......1 """ if n == 1 : return 1 else : return n * factorial_recursive(n - 1 ) # 5 * factorial_recursive(4) # 5 * 4 * factorial_recursive(3) # 5 * 4 * 3 * factorial_recursive(2) # 5 * 4 * 3 * 2 * factorial_recursive(1) # 5 * 4 * 3 * 2 * 1 = 120 # 0 1 1 2 3 5 8 13 def fibonacci (n): if n == 1 : return 0 elif n == 2 : return 1 else : return fibonacci(n - 1 ) + fibonacci(n - 2 ) number = int ( input ( "Enter then number \n " )) # print("Factorial Using Iterative Method", factorial_it...
Read more