Sets and Type Convertions

Question 1

What is the syntax for creating a set?

Answer 1

my_set = {1, 2, 3}.

Question 2

How to create an empty set?

Answer 2

Use set(): my_set = set() (not {}, which creates a dictionary).

Question 3

What is the key property of sets?

Answer 3

Sets store unique elements (no duplicates).

Question 4

How to add an element to a set?

Answer 4

Use .add(item) (e.g., my_set.add(4) → {1,2,3,4}).

Question 5

How to add multiple elements to a set?

Answer 5

Use .update(): my_set.update([4,5]) → {1,2,3,4,5}.

Question 6

How to remove an element from a set?

Answer 6

Use .remove(item) (raises error if item is missing) or .discard(item) (no error).

Question 7

How to remove and return an arbitrary element from a set?

Answer 7

Use .pop() (e.g., my_set.pop() → removes and returns an element).

Question 8

How to clear all elements from a set?

Answer 8

Use .clear(): my_set.clear() → set().

Question 9

How to check if an element exists in a set?

Answer 9

Use in: 2 in {1,2,3} → True.

Question 10

What is the union of two sets?

Answer 10

Use .union() or |: {1,2}.union({2,3}) → {1,2,3}.

Question 11

What is the intersection of two sets?

Answer 11

Use .intersection() or &: {1,2}.intersection({2,3}) → {2}.

Question 12

What is the difference between two sets?

Answer 12

Use .difference() or -: {1,2}.difference({2,3}) → {1}.

Question 13

What is the symmetric difference between two sets?

Answer 13

Use .symmetric_difference() or ^: {1,2}.symmetric_difference({2,3}) → {1,3}.

Question 14

How to check if one set is a subset of another?

Answer 14

Use .issubset(): {1,2}.issubset({1,2,3}) → True.

Question 15

How to check if one set is a superset of another?

Answer 15

Use .issuperset(): {1,2,3}.issuperset({1,2}) → True.

Question 16

How to create a set from a list?

Answer 16

Use set(): set([1,2,2]) → {1,2}.

Question 17

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Answer 17

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Question 18

How to convert a string to an integer?

Answer 18

Use int(): int('5') → 5.

Question 19

How to convert a string to a float?

Answer 19

Use float(): float('3.14') → 3.14.

Question 20

How to convert a number to a string?

Answer 20

Use str(): str(10) → '10'.

Question 21

How to convert a list to a tuple?

Answer 21

Use tuple(): tuple([1,2,3]) → (1,2,3).

Question 22

How to convert a tuple to a list?

Answer 22

Use list(): list((1,2,3)) → [1,2,3].

Question 23

How to convert a list to a set?

Answer 23

Use set(): set([1,2,2]) → {1,2}.

Question 24

How to convert a set to a list?

Answer 24

Use list(): list({1,2}) → [1,2].

Question 25

How to convert a dictionary to a list of keys?

Answer 25

Use `list()`: `list({'a':1})` → `['a']`.

Question 26

How to convert a dictionary to a list of values?

Answer 26

Use `list()` with `.values()`: `list({'a':1}.values())` → `[1]`.

Question 27

How to convert a dictionary to a list of key-value pairs?

Answer 27

Use `list()` with `.items()`: `list({'a':1}.items())` → `[('a',1)]`.

Question 28

How to convert a string to a list of characters?

Answer 28

Use `list()`: `list('hello')` → `['h','e','l','l','o']`.

Question 29

How to convert a list of strings to a single string?

Answer 29

Use `join()`: `''.join(['h','e','l','l','o'])` → `'hello'`.

Question 30

How to convert a number to a boolean?

Answer 30

Use `bool()`: `bool(1)` → `True`, `bool(0)` → `False`.

Question 31

How to convert a string to a boolean?

Answer 31

Non-empty strings are `True`; empty strings are `False` (e.g., `bool('text')` → `True`).

Question 32

How to convert a list to a boolean?

Answer 32

Non-empty lists are `True`; empty lists are `False` (e.g., `bool([1,2])` → `True`).