week 3 - types

Question 1

string

Answer 1

sequence of characters that can be stored in a variable, immutable

Question 2

string literal

Answer 2

string value specified in the source code of the program

Question 3

sequence type

Answer 3

type that is a specified collection of objects ordered from left to right

position in sequence is called index

Question 4

len()

Answer 4

function that returns number of elements in a sequence type

Question 5

brackets []

Answer 5

used to index a sequence type

Question 6

alphabet[0] returns…

Answer 6

A

Question 7

alphabet[-1]

Answer 7

last character (Z)

Question 8

how to update strings

Answer 8

assign an entirely new string, you can’t edit because its immutable

Question 9

string concatenation

Answer 9

adding a new character at the end of a string

Question 10

container

Answer 10

construct to group related values together and contain references to other objects instead of data

Question 11

list

Answer 11

container created by sequence of variables or literals with brackets

Question 12

element

Answer 12

list item

Question 13

index

Answer 13

position of element in list, starting with 0

Question 14

updating list elements

Answer 14

lists are mutable and can change through re-assignment

Question 15

method

Answer 15

instructs object to preform some action, executed by specifying method name with “.” and object identifier

Question 16

append.identifier(value)

Answer 16

adds value to end of list

Question 17

pop.identifier(1)

Answer 17

removes element at index

Question 18

remove.identifier(value)

Answer 18

removes first element that matches value

Question 19

sequence type function

Answer 19

built in functions that operate on sequences like lists/strings

Question 20

sequence type methods

Answer 20

methods built into class definitions of sequences like lists/strings

Question 21

list.index(v)

Answer 21

find index of 1st element who’s value is v

Question 22

list.count(v)

Answer 22

count occurrences of v in list

Question 23

tuple

Answer 23

immutable collection of data, sequence type
made with paranthesis

Question 24

when are tuples usually used?

Answer 24

when element position is important

Question 25

named tuple

Answer 25

allows program to define a simple new data type that consists of named attributes

Question 26

car.price
car.horsepower
what’s the name of the tuple?

Answer 26

car

Question 27

what must you do to use named tuples?

Answer 27

import namedtuple

Question 28

creating named tuples

Answer 28

car = namedtuple(‘car’, [‘make,’, ‘mode’, ‘price’])

Question 29

set

Answer 29

unordered collection of unique elements, sequential obj only

Question 30

does a set have postions/indeces?

Answer 30

NO

Question 31

can more than one element share the same value in a set?

Answer 31

NO

Question 32

set()

Answer 32

function to make a set, elements can be lists, tuples, strings, etc. used to make empty sets

Question 33

set literal

Answer 33

written using {}

Question 34

set.add()

Answer 34

places new elements into the set

Question 35

set.remove()

Answer 35

takes out specific element from set

Question 36

set.pop()

Answer 36

takes out random element from set

Question 37

set1.update(set2)

Answer 37

adds elements of set2 to set1

Question 38

set1.clear()

Answer 38

removes all elements from set

Question 39

set.intersection(set1, set2, set3)

Answer 39

returns new set only with elements in common between set and inserted sets

Question 40

set.union(set1, set2, set3)

Answer 40

returns new set with all unique elements between sets

Question 41

set.difference(set1, set2, set3)

Answer 41

only returns set elements not found in inserted sets

Question 42

set.symmetric_difference(setb)

Answer 42

returns elements only with elements once in either a or b

Question 43

max(list)

Answer 43

finds max value in list

Question 44

sum(list)

Answer 44

adds all numeric elements in list

Question 45

set.sort()

Answer 45

rearranges biggest to smallest

Question 46

string.split()

Answer 46

splits string into list, default delimiter is space

Question 47

dictionary

Answer 47

collection of key value pairs where you can quickly look up values if you know the key

Question 48

accessing certain key in dictionary

Answer 48

age[‘ellen’]

Question 49

list(), tuple()

Answer 49

conversion functions

Question 50

dict

Answer 50

object type for dictionary

Question 51

key

Answer 51

term located in dictionary that is associated with a value, immutable

Question 52

value

Answer 52

describes some data associated with key, ex: definition

Question 53

making a dictionary

Answer 53

players = {‘Messi’: 10, ‘Ronaldo’: 7}

Question 54

empty dictionary

Answer 54

{}

Question 55

accessing dictionary entries

Answer 55

index with specific key in brackets

Question 56

keyerror

Answer 56

runtime error

Question 57

adding new entry to end of dict

Answer 57

prices[‘banana’] = 4.00

Question 58

removing entries

Answer 58

del prices[‘papayas’]

Question 59

adding entries

Answer 59

dict[k] = v -> adds new key value pair

Question 60

numeric types

Answer 60

int and float, store data and support normal math operations

Question 61

mapping types

Answer 61

dict, container where each element is independent with no ordering or relation to other elements

Question 62

type conversion

Answer 62

convert between types

Question 63

implicit conversion

Answer 63

automatically made by interpreter, usually through operations

Question 64

int()

Answer 64

converts float to int without rounding, simply removes fractional part