EDS 217 Cheatsheet

Creating Sets

Code

# Empty set
empty_set = set()
print(f"Empty set: {empty_set}")

# Set from a list
set_from_list = set([1, 2, 3, 4, 5])
print(f"Set from list: {set_from_list}")

# Set literal
set_literal = {1, 2, 3, 4, 5}
print(f"Set literal: {set_literal}")

Empty set: set()
Set from list: {1, 2, 3, 4, 5}
Set literal: {1, 2, 3, 4, 5}

Basic Operations

Code

s = {1, 2, 3, 4, 5}
print(f"Initial set: {s}")

# Add an element
s.add(6)
print(f"After adding 6: {s}")

# Remove an element
s.remove(3)  # Raises KeyError if not found
print(f"After removing 3: {s}")

s.discard(10)  # Doesn't raise error if not found
print(f"After discarding 10 (not in set): {s}")

# Pop a random element
popped = s.pop()
print(f"Popped element: {popped}")
print(f"Set after pop: {s}")

# Check membership
print(f"Is 2 in the set? {2 in s}")

# Clear the set
s.clear()
print(f"Set after clear: {s}")

Initial set: {1, 2, 3, 4, 5}
After adding 6: {1, 2, 3, 4, 5, 6}
After removing 3: {1, 2, 4, 5, 6}
After discarding 10 (not in set): {1, 2, 4, 5, 6}
Popped element: 1
Set after pop: {2, 4, 5, 6}
Is 2 in the set? True
Set after clear: set()

Set Methods

Code

a = {1, 2, 3}
b = {3, 4, 5}
print(f"Set a: {a}")
print(f"Set b: {b}")

Set a: {1, 2, 3}
Set b: {3, 4, 5}

Union

Code

union_set = a.union(b)
print(f"Union of a and b: {union_set}")

Union of a and b: {1, 2, 3, 4, 5}

Intersection

Code

intersection_set = a.intersection(b)
print(f"Intersection of a and b: {intersection_set}")

Intersection of a and b: {3}

Difference

Code

difference_set = a.difference(b)
print(f"Difference of a and b: {difference_set}")

Difference of a and b: {1, 2}

Symmetric difference

Code

symmetric_difference_set = a.symmetric_difference(b)
print(f"Symmetric difference of a and b: {symmetric_difference_set}")

Symmetric difference of a and b: {1, 2, 4, 5}

Subset and superset

Code

is_subset = a.issubset(b)
is_superset = a.issuperset(b)
print(f"Is a a subset of b? {is_subset}")
print(f"Is a a superset of b? {is_superset}")

Is a a subset of b? False
Is a a superset of b? False