u02-slides-conditions-loops-flashcards

Question 1

What are the three main logical operations in Python?

Answer 1

not, or, and

Question 2

What is short-circuit evaluation in Python?

Answer 2

For ‘or’, if first expression is True, second is skipped. For ‘and’, if first is False, second is skipped.

Question 3

What objects are interpreted as False in Python?

Answer 3

The special value None, the value 0 of all numeric types, and empty sequences

Question 4

What is the purpose of assertions in Python?

Answer 4

To implement sanity checks that raise an error if a condition evaluates to False - useful for debugging

Question 5

How can assertions be disabled in Python?

Answer 5

By running Python with the -O option (python -O …)

Question 6

What are the main branching statements in Python?

Answer 6

if, elif, and else statements

Question 7

How is code within branches assigned in Python?

Answer 7

Through indentation (typically 4 spaces) rather than braces

Question 8

What is pattern matching in Python?

Answer 8

A feature introduced in Python 3.10 that allows structural pattern matching using the match statement

Question 9

What are the two main types of loops in Python?

Answer 9

while loops and for loops

Question 10

What is the difference between while and for loops?

Answer 10

while loops repeat based on a condition being True, for loops iterate over elements in an iterable

Question 11

What are common use cases for while loops?

Answer 11

Asking for input until correct, running main routines until stopped, optimization until convergence

Question 12

What is a potential danger with while loops?

Answer 12

They can lead to endless/infinite loops if the condition is never False

Question 13

What is an iterable in Python?

Answer 13

A sequence of elements that can be iterated over (e.g., strings, data structures)

Question 14

What keywords can manually control loop execution?

Answer 14

break (to exit the loop) and continue (to jump to next iteration)

Question 15

Why should manual loop control keywords be used sparingly?

Answer 15

They break the normal control flow of the program by creating sudden jumps in code

Question 16

How do you write a chained comparison in Python?

Answer 16

You can chain operators, e.g., 3 < 4 < 5

Question 17

What happens if there’s no else statement in an if-elif chain?

Answer 17

No branch might be executed at all

Question 18

What’s the syntax for adding a message to an assertion?

Answer 18

assert condition, “message”

Question 19

When should assertions not be used?

Answer 19

For general error/exception handling (since users can disable them)

Question 20

How do you write a for loop to iterate over a string?

Answer 20

“for char in my_string:”

Question 21

What is the typical indentation size in Python?

Answer 21

4 spaces

Question 22

How are multiple conditions evaluated in if-elif-else chains?

Answer 22

From top to bottom

Question 23

What is the default case in pattern matching called?

Answer 23

The underscore (_) case

Question 24

What happens to code after a break or continue statement?

Answer 24

It is ignored within that loop iteration