Python Data Type: Sets

Creating Sets

a = {1, 2, 3, 4, 5}
b = {5, 4, 3, 2, 1}
print(a)  # Prints {1, 2, 3, 4, 5}
print(b)  # Prints {1, 2, 3, 4, 5}

# No Duplicate Entries can be added to set
c = {3, 3, 2, 1, 0}
print(c)  # Prints {0, 1, 2, 3}

# We cannot add list, tuple or dictionary in Set
d = set()
e = {}
print(type(d))  # Prints <class 'set'>
print(type(e))  # Prints <class 'dictionary'>

Accessing set

print(a)

We cannot access set by index number. Because no any item is associated to specific index number

Deleting set and its elements

del a
b.discard(1)
b.remove(2)

# Difference between discard and remove is: if the element is not found discard don't give error message but remove give
b.pop()  # Removes an arbitrary element
b.clear()

Updating elements in the set

# add()
b.add(1)
b.add(4)
b.add(3)
b.add(2)
print(b)  # Prints {1, 2, 3, 4}

# update()
c.update([4, 5], {6, 7, 8}, (9, 10))

print(c)  # Prints {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
# We cannot nest list, tuple, dictionary and set inside a set but we can form set from list, tuple and dictionary.

Functions in Set

s1 = {4, 5, 2, 3, 1, 6}
s2 = {"Friday", "Sunday", "Saturday", "Wednesday", "Monday", "Thursday", "Tuesday"}

# len
print(len(s1))

# max
print(max(s1))
print(max(s2))  # Prints Wednesday

# The Python function returned ‘Wednesday’ because W has the highest ASCII value among M, T, W, F, and S.
# min()
print(min(s1))
print(min(s2))  # Prints Friday

# sun()
print(sum(s1))

# any()
print(any({0, "0"}))  # Prints True

# all()
print(all({0, "0"}))  # Prints False

# sorted()
print(sorted(s1))

Methods in Set

# union()
# First Method:
print(s1 | s2)
# Second Method:
print(s1.union(s2))

# intersection()
# First method:
print(s1 & s2)
# Second Method:
print(s1.intersection(s2))

# difference:
# The difference() method returns the difference of two or more sets.
# It returns as a set.
print(s1 - s2)
print(s1.difference(s2))

# symmetric difference:
# This method returns all the items that are unique to each set.
print(s1.symmetric_difference(s2))

# intersection_update: The result of intersection is updated to given set
s1 = {1, 2, 3}
s2 = {3, 4, 5}
s1.intersection_update(s2)
print(s1)  # Prints {3}

# difference_update: The result of difference is updated to given set
s1 = {1, 2, 3}
s2 = {3, 4, 5}
s1.difference_update(s2)
print(s1)  # Prints {1, 2}

# Symmetric_difference_update: The result of symmetric_difference is updated to given set
s1 = {1, 2, 3}
s2 = {3, 4, 5}
s1.symmetric_difference_update(s2)
print(s1)  # Prints {1, 2, 4, 5}

# copy
s1 = s2.copy()

# isdisjoint(): This method returns True if two sets have a null intersection. However, it can take only one argument.
print({1, 3, 2}.isdisjoint({4, 5, 6}))

# issubset()
print({1, 2}.issubset({1, 2, 3}))
# Prints True because {1,2} is a proper subset of {1,2,3}

print({1, 2}.issubset({1, 2}))
# Prints True because {1,2} is an improper subset of {1,2}.

# issuperset(): this one returns True if the set contains the set in the argument.
print({1, 3, 4}.issuperset({1, 2}))

# Prints False because {1,2} is not present in {1,3,4}
print({1, 3, 4}.issuperset({1}))  # Prints True because {1} is present in {1,3,4}

Operations on Set

# Membership:
print("p" in {"a", "p", "p", "l", "e"})

Python Boolean

a = True
b = False
a1 = "True"
b1 = "False"
print(type(a))  # Prints <class 'bool'>
print(type(a1))  # Prints <class 'str'>
print(type(b))  # Prints <class 'bool'>
print(type(b1))  # Prints <class 'str'>
print(bool("abcd"))  # Prints True
print(bool())  # Prints False
print(bool([]))  # Prints False
print(bool(0))  # Prints False
print(bool(1))  # Prints True
print(bool(2))  # Prints True
print(bool(0.00000000000001))  # Prints True
print(bool(""))  # Prints False
print(bool(" "))  # Prints True
print(True + False)  # Prints 1 because 1 + 0 = 1
print(True + True)  # Prints 2 because 1 + 1 = 2
print(False + False)  # Prints 0 because 0 + 0 = 0
print(False - True)  # Prints -1 because 0 - 1 = -1
print(False / True)  # Prints 0.0
print(True % True)  # Modulus operation
print(True**True)  # Exponential Operation
print(True > False)  # Prints True
print(True is False)  # Prints False