Built-In Methods

Question 1

abs(x)

Answer 1

abs(x)
accepts an integer or a float
returns the absolute value of that number

Question 2

all()

Answer 2

accepts an iterable

returns true if ALL elements in the iterable are True

Question 3

any()

Answer 3

accepts an iterable

returns true if ANY element in the iterable is True

Question 4

ascii()

Answer 4

accepts any object (strings, Tuples, lists)

returns a readable version of object and replaces any non-ascii chars with escaped chars

Question 5

bool()

Answer 5

accepts an object

returns a boolean value after standard truth-testing procedure

This always returns true unless…
object is empty like: [] {} ()
object is False
object is zero
object is None

Question 6

callable()

Answer 6

accepts an Object

returns True if X is callable

for example, built-in functions and classes are both callable

Question 7

delattr()

Answer 7

delattr(object, str)

deletes a property from an object, does not return anything.

string must be one of the objects attributes

Question 8

dict()

Answer 8

Accepts keyword arguments
Returns a new python dictionary

example:
dict(name = “John”, age = 36, country = “Norway”)

Question 9

enumerate()

Answer 9

enumerate(iterable, start=0)

start = the index value from which the counter is to be started

returns an enumerate object with index/element pairsfromat

example:
seasons = [‘spring’, ‘summer’, ‘fall’, ‘winter’]
list(enumerate(seasons))
// [(0, ‘spring’), (1, ‘summer’), (2, ‘fall’), (3, ‘winter’)]

Question 10

filter()

Answer 10

filter(truth-test function, iterable)

returns the elements in the iterable that return true in the filter function

use list() to view results

example:
seasons = [‘spring’, ‘summer’, ‘fall’, ‘winter’]
def filter_func(item):
return len(item) == 4

list(filter(filter_func, seasons)
// [‘fall’]

Question 11

eval()

Answer 11

eval(string)

evaluates the specified expression

eval(“3+1”) = 4

Question 12

exec()

Answer 12

exec(object)
executes the specified Python code

NOTE: eval() can only accept a single expression
Whereas exec() can accept large blocks of code

Question 13

float()

Answer 13

accepts a number or a string

returns a floating-point number

Question 14

getattr()

Answer 14

getattr(object, attribute, default)

returns object[attribute] if attribute is available
or default value if provided
otherwise, returns AttributeError

Question 15

hasattr()

Answer 15

hasattr(object, attribute)

checks if object has the given named attribute

returns True / False

Question 16

hash()

Answer 16

hash(object)

returns hashed value if possible

Question 17

int()

Answer 17

int(number or string)

returns specified value in integer format

it

Question 18

len()

Answer 18

len(object)

returns the number of items in an object
returns the number of chars in a string

data

Question 19

list()

Answer 19

list(iterable)

returns a Python list

list(“ABCDEF”)
[“A”, “B”, “C”, “D”, “E”, “F”]

list({‘A’: 1, ‘B’: 2, ‘C’: 3, ‘D’: 4, ‘E’: 5})
[“A”, “B”, “C”, “D”, “E”, “F”]

list()
[]

Question 20

map()

Answer 20

map(function, iterable)

returns a “map object” which is the result of applying function to each element in the input iterable

need to pass the object to list() or tuple()

def addition(n):
return n+n

list(map(addition, [0,1,2])
[0,2,4]

Question 21

max()

Answer 21

max(iterable)
max(a, b, c, d)

returns the largest item in the iterable or the largest of 2 or more arguments

Question 22

min()

Answer 22

min(iterable)
min(a, b, c, d)

returns the smallest item in the iterable or the smallest of 2 or more arguments

Question 23

next()

Answer 23

next(iterator)

returns the next item in an iterator

mylist = iter([“apple”, “banana”, “cherry”])
x = next(mylist)
//”apple”
x = next(mylist)
//”banana”
x = next(mylist)
//”cherry”

Question 24

open()

Answer 24

open(file_name, mode)

modes:
“r” = read (default)
“w” = write
“a” = append
“x” = create

opens a file, returns it as a file object

Question 25

pow()

Answer 25

pow(base, exponent)

returns base to the power of exponent

pow(2,3) = 2^3 = 8

Question 26

range()

Answer 26

range(start=0, stop, step=1)

returns a sequence of numbers starting at start, in increments of step, ending before stop

Question 27

repr()

Answer 27

repr(object)

returns a readable string without formatting or rounding

Question 28

reversed()

Answer 28

reversed(iterable)

returns an iterator that accesses the given sequence in reverse order

Question 29

round()

Answer 29

round(number, digits=0)

returns a floating-point number that is rounded to the specified number of decimals

round(8.5) = 8
round(8.5, 1) = 8.5

Question 30

set()

Answer 30

set(iterable, sequence-like list)

returns a non-repeating element iterable

set((3, 4, 1, 4, 5)) = {1, 3, 4, 5}
set(range(3)) = {0, 1, 2}

Question 31

setattr()

Answer 31

setattr(object, attribute, value)

can be used to assign a new value to an object attribute, or initialize a new object attribute

Question 32

sorted()

Answer 32

sorted(iterable, key=None, reverse=False)
iterable = list, tuple, dictionary, etc
key = a function to execute to decide the order
reverse = False (Ascending) and True (Descending)

sorted({0: ‘this’, 9: ‘that’, 7: ‘whatever’})
[0, 7, 9]

sorted([9,2,7,5,6])
[2, 5, 6, 7, 9]

Question 33

str()

Answer 33

str(object)

converts specified value to a string

Question 34

sum()

Answer 34

sum(iterable, start)

returns the sum of all items in an iterable

Question 35

tuple()

Answer 35

tuple(iterable)

returns a tuple object

Question 36

type()

Answer 36

type(object)
returns the type of an object