Unit 3

Question 1

What is a string?

Answer 1

an immutable sequence of characters stored in a variable

Question 2

3.1 - String Basics

How do you find the length of a string?

Answer 2

len(string)

Question 3

3.1 - String Basics

What is string concatenation?

Answer 3

combining string values in an output statement

Question 4

3.2 - List Basics

What is a container?

Answer 4

a construct which groups related objects together

individual components are called elements

Question 5

3.2 - List Basics

What is a list?

Answer 5

an ordered mutable container, uses square brackets []

Question 6

3.2 - List Basics

How do you concatenate lists?

use ‘list1’ and ‘list2’ as list names

Answer 6

list1 + list2

Question 7

3.2 - List Basics

What are the four commands you can do for lists?

format answers as code

Answer 7

list.append(v) adds new element
list.pop(i) removes an element at index (i)
list.remove(v) removes an element with value (v)
list.index(v) finds a value (v)’s index

Question 8

3.3 - Tuple Basics

What is a tuple?

Answer 8

an ordered immutable container, uses ()

Question 9

3.3 - Tuple Basics

What does a named tuple do?

Answer 9

allows a programmer to name each element

Car = namedtuple('Car', ['model', 'price']

blazer = Car('Chevrolet', 32000')

Question 10

3.4 - Set Basics

What is a set?

Answer 10

a mutable, unordered container with unique elements; uses set() or {}

{} used for literals

Question 11

3.4 - Set Basics

What are the four commands you can do for sets?

use ‘setA’, ‘setB, etc. for set examples

Answer 11

set.intersection(setA, setB) set w/ elements in common
set.union(setA, setB) set w/ unique elements
setA.difference(setB, setC) set w/ unique elements from setA
setA.symmetric_difference(setB) set w/ elements that appear only once in setA/setB

Question 12

3.5 - Dictionary Basics

What is a dictionary?

Answer 12

a mutable key/value paired collection, uses {'a': 1}

‘a’: 1 is a sample element for a dictionary

Question 13

3.5 - Dictionary Basics

What is the difference between a key and a value?

Answer 13

key: index, like a term
value: mutable value, like a definition

Question 14

3.5 - Dictionary Basics

What are the three commands you can use for dictionaries?

dictionary name: numbers
key: ‘one’, ‘two’, etc.
value: 1, 2, etc.

Answer 14

numbers["one"] references value from key
numbers['three'] = 3 creates/updates entries
del numbers['two'] removes an entry

Question 15

3.6 - Common Data Types

What are the 5 data types?

Answer 15

string: sequence type, text
list: sequence type, ordered elements, mutable
tuple: sequence type, ordered elements, immutable
set: set type, unordered/unique elements, mutable
dict: mapping type, key/value elements, mutable

Question 16

3.8 - Type Conversions

What are the three ways to convert types?

Answer 16

int() for integers/floats/int strings
float() for integers/floats/fractions/int strings
str() for all types

Question 17

3.9 - Binary Numbers

What is binary?

Answer 17

a base 2 number system; the basis for machine language

ex. 10 = 0110

10 / 8 = 2
2 / 2 = 0

Question 18

3.10 - String Formatting

How do you use string formatting?

give an example code

Answer 18

`print(f’{value}’)

Question 19

3.10 - String Formatting

What are the different ways to represent value in text?

10 total options

Answer 19

:s string (default)
:d decimal (base 10)
:,d decimal w/ commas
:03d leading 0 notation*
:b binary
:x or :X hexadecimal (upper/lower)
:e exponent
:f fixed point, 6 places
:.2f fixed point, 2 places*
:,.2f see above, w/ commas

• • 3 is replacable with any number, ex. 004
• • 2 is replacable, ex. .04

Question 20

3.15 - zyLab

How do you get the 2 rightmost digits of a number?

123 -> 23

Answer 20

123 % 100

123 % 100 = 23

Question 21

3.15 - zyLab

How do you shift a number to the right 2 digits?

123 -> 1

Answer 21

123 // 100

123 // 100 = 1

Question 22

Extra

What does ** do?

Answer 22

exponent

ex. 3 ** 2 = 9

basically, ** can be treated as ^
ex. 3^2 = 9