Union and intersection in Python - Cheat Sheet & Quick Revision

Recall & Review

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What is the union of two sets in Python?

The union of two sets is a new set containing all unique elements from both sets. It combines elements without duplicates.

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What does the intersection of two sets represent?

The intersection of two sets is a new set containing only the elements that appear in both sets.

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How do you find the union of sets a and b in Python?

You can use a.union(b) or the | operator like a | b.

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How do you find the intersection of sets a and b in Python?

You can use a.intersection(b) or the & operator like a & b.

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If a = {1, 2, 3} and b = {3, 4, 5}, what is a | b and a & b?

a | b is {1, 2, 3, 4, 5} (union), and a & b is {3} (intersection).

Which operator gives the union of two sets a and b in Python?

A |

B &

C ^

D -

The | operator returns the union of two sets.

What does a & b return when a and b are sets?

A Intersection of a and b

B Difference of a and b

C Union of a and b

D Symmetric difference of a and b

The & operator returns the intersection of two sets.

Which method can be used to find the union of two sets a and b?

A a.intersection(b)

B a.difference(b)

C a.union(b)

D a.symmetric_difference(b)

The union() method returns the union of two sets.

If a = {1, 2} and b = {2, 3}, what is a & b?

A {1, 2, 3}

B {1}

C set()

D {2}

The intersection contains only elements common to both sets, which is {2}.

What will a | b return if a = {5, 6} and b = {6, 7}?

A {6}

B {5, 6, 7}

C {5, 7}

D {}

The union combines all unique elements from both sets.

Explain in your own words what the union and intersection of two sets mean.

Think about combining two groups of friends versus finding friends you both have.

Describe how to find the union and intersection of two sets in Python using operators and methods.

Remember the symbols look like OR and AND.