The false bible of commands

Question 1

what does random() do?

Answer 1

random real number between 0 and 1 (not inclusive of 1, but 0 works)

Question 2

what does randint() do?

Answer 2

returns random integer between a and b INCLUSIVELY (and doesnt work when not provided a range)

Question 3

what happens if you get an undefined error?

Answer 3

you redefined a core python function/something and is now uncallable, reset python immediately

Question 4

are while true loops allowed?

Answer 4

NAH

Question 5

.title()

Answer 5

capitalizes first letter, lowercases all others

Question 6

what does the keyword del do?

Answer 6

deletes a variable from memory

Question 7

repr()

Answer 7

returns exactly what string you put in, NOT including quotations (but also performs actions like 1+3 within it, and if you do a list like [1, 4, 2] it wont capture the weird space, and also always single quotes for everything even if you do repr(“hiello”)

Question 8

abs()

Answer 8

returns absolute value of smth, either in or float or 0 or 1 when used on a boolean, part of standard python (no import needed)

Question 9

ord()

Answer 9

standard python, converts string input to integer equivalent in unicode code

Question 10

chr()

Answer 10

standard python, converts to single letter string from unicode code input

Question 11

len()

Answer 11

standard python, returns length of any iterable data sequence (tuple, string, list)

Question 12

del

Answer 12

keyword in standard python, deletes variables and elements of mutable data sequences, alterring the sequence itself (deletes parts of lists if you want it to and lessens length by 1 every time)

Question 13

list()

Answer 13

standard python, typecasts something iterable to a list (does not work on floats or ints or booleans) (tuples and strings work though)

Question 14

shuffle()

Answer 14

random module, randomly organizes items in data sequence. original object is mutated, DOES NOT CREATE NEW OBJECT
shuffle(x)

Question 15

in

Answer 15

standard python keyword, returns boolean True or False if x is found anywhere in data sequence y (does not work on ints or floats or bools) (works on tuples and strings)

x in y = True or False

Question 16

max() and min()

Answer 16

standard python, returns highest and lowest value in data sequence (even works to compare booleans and strings though you prob dont need that)

Question 17

sum()

Answer 17

standard python, sums numbers in list (works on everything BUT strings)

sum(x)

Question 18

mean()

Answer 18

statistics class, CANNOT be used on strings, returns average of data sequence elements

Question 19

median()

Answer 19

statistics class, can be used on strings, returns middlemost element of data sequence

Question 20

mode()

Answer 20

statistics class, can be used on strings, returns most common element of data sequence

Question 21

multimode()

Answer 21

statistics class, mode but returns list and list can contain multiple “most common elements” of any data sequence

Question 22

reverse()

Answer 22

list.reverse()
ONLY WORKS ON MUTABLE DATA SEQUENCE TYPES
reverses all elements in sequence

Question 23

append

Answer 23

list.append(x)

adds ONE item to end of MUTABLE data sequence

Question 24

pop

Answer 24

x.pop(i)

removes item at INDEX i from MUTABLE sequence x, UNLIKE OTHER SEQUENCE METHODS returns item removed

no index = defaults to i = -1, or last item in the list

Question 25

insert

Answer 25

x.insert(2, y) inserts y into x at index 2 of MUTABLE data sequence DOES NOT DELETE PREVIOUS ITEM AT THAT INDEX

Question 26

extend

Answer 26

x.extend([y]) adds list y's elements to end of MUTABLE sequence x append would have just added a nested list

Question 27

count

Answer 27

list.count(x) returns the number of occurrences of x in a list (works on all data sequences)

Question 28

index

Answer 28

x.index(y) returns the index of y within x (works on all data sequences)

Question 29

remove

Answer 29

x.remove(y) removes item y in x (NOT index location), works on MUTABLE data sequence

Question 30

clear

Answer 30

x.clear() turns mutable sequence x into empty list

Question 31

sort

Answer 31

ONLY WORKS ON LISTS list.sort() sorts list by ascending order (by default), or by descending if reverse flag set to true sorts list IN PLACE, does not return anything ex. numlist.sort(reverse=True)

Question 31

sorted

Answer 31

sorted(numlist) RETURNS sorted list, does not change list itself works on any iterable

Question 31

range

Answer 31

range(n) or range(number included, n) goes from number included to n-1, creating object of type range creates ITERATOR object one by one to n-1 to complete the whole iterator range(x, y, z) goes from x to y-1 in steps of z, and steps can also be negative just like slices of strings

Question 32

iter

Answer 32

iter(x) determines whether input can be iterated through, as with a list or a variable set to equal range(n)

Question 33

next

Answer 33

next(x) returns next value in iterator, first call will return the lowest number in the iterator by default (ex. next(range(n)) = 0)

Question 34

enumerate

Answer 34

returns the index and the item itself of a data sequence in that specific order, can be used with two iterators in a for loop to get both as separate or only one iterator to be assigned a tuple pair (index, item) index, item = enumerate(x)

Question 35

choice

Answer 35

choice(data sequence) selects random element

Question 36

difference between +=, append, and extend for adding tuples?

Answer 36

+= and extend only add the values to the end, whereas append adds the actual tuple

Question 37

set function

Answer 37

set(x) returns a list with only one of each instance

Question 38

id

Answer 38

id(x) returns memory location variable or value points to/is stored in respectively

Question 39

copy

Answer 39

x.copy() returns deep copy of list???

Question 40

capitalize

Answer 40

x.capitalize() returns string with first letter capitalized

Question 41

title

Answer 41

x.title() returns string with first and all words separated by space to be capital letters

Question 42

swapcase

Answer 42

x.swapcase() returns opposite case string ("hELLO" ---> "Hello")

Question 43

strip

Answer 43

x.strip() removes leading and trailing (but not middle) spaces

Question 44

lstrip

Answer 44

x.lstrip() returns string w/o left or leading spaces

Question 45

rstrip

Answer 45

x.rstrip() returns string w/o right or trailing spaces

Question 46

center, ljust, rjust

Answer 46

x.function(y, char) y = amnt of spaces char = fill character (automatically spaces) returns centered, left justified , and right justified strings respectively if odd, one extra trailing space/character is addded

Question 47

zfill

Answer 47

x.zfill(num) num = amnt of 0's adds a bunch of leading zeroes requires argument

Question 48

join

Answer 48

char.join(iterable) iterable = iterable like a list char = the intended space character/string (cant be number or boolean)

Question 49

split

Answer 49

x.split(separator, maxsplit=) splits string into list of terms separated by separator separator is not included in list if delimiter is not a space, consecutive delimiters are treated as empty strings in the returned string maxsplit = amount of splits desired (1 split = 2 components)

Question 50

rsplit

Answer 50

same as split but from the right, useful when maxsplit is specified

Question 51

splitlines

Answer 51

same as split but takes newlines as delimiters

Question 52

partition

Answer 52

x.partition(separator) returns a tuple with 3 parts: the string left of the separator, the separator, and to the right of the separator works on 1st instance of separator left, seperator, right = x.partition(seperator)

Question 53

rpartition

Answer 53

partition but starts at instance of partition to the right/last instance

Question 54

find

Answer 54

x.find(inside) returns index of first instance but returns -1 not error when not found

Question 55

rfind and rindex

Answer 55

find and index but from the right

Question 56

replace

Answer 56

x.replace(thing, replacement) x.replace(thing, replacement, # of times thing should be replaced) replaces

Question 57

startswith and endswith

Answer 57

obvi

Question 58

isalpha

Answer 58

x.isalpha() True if all alphabetic chars, if not or empty = False

Question 59

isalnum

Answer 59

x.isalnum() True if chars are alphanumeric false if not

Question 60

isdigit

Answer 60

x.isdigit()

Question 61

ascii_uppercase, ascii_lowercase, ascii_letters, digits

Answer 61

constants of string module: 1. uppercase alphabet 2. lowercase alphabet 3. lower + upper alphabets concatenated 4. all digits 0123456789

Question 62

capitalize

Answer 62

x.capitalize() capitalizes just the first letter in the string, even if its a space

Question 63

array()

Question 64

dtype

Answer 64

dtype = and myarray.dtype (no parenthesis)

Question 65

shape size ndim

Answer 65

no parenthesis for any, no np dot thingy

Question 66

arange

Answer 66

np.arange(start, end (uninclusive), steps)

Question 67

linspace

Answer 67

np.linespace(start, end, amount of linearly spaced points between) np.linespace(start, end (inclusive), amount of linearly spaced points between, dtype=int)

Question 68

vstack

Answer 68

np.vstack((array1, array2)), stacks vertically, takes single tuple argument

Question 69

hstack

Answer 69

np.hstack((array1, array2)) stacks horizontally (same row), takes single tuple argument

Question 70

zeros ones full empty

Answer 70

np.zeros((# of arrays, rows of arrays, cols of arrays), dtype=whatevs) np.zeros((rows, cols)) np.zeroes(cols) np.ones() ^same as above np.full((# of arrays, rows of arrays, cols of arrays), number to put in array, dtype=whatevs) of arrays part can be removed https://numpy.org/doc/stable/reference/generated/numpy.zeros.html

Question 71

default rng

Answer 71

np.random.default_rng()

Question 72

random

Answer 72

np.random.default_rng().random(x)

Question 73

integers

Answer 73

np.random.default_rng().integers(start, end, cols) np.random.default_rng().integers(start, end, (rows, cols)

Question 74

logical indexing

Answer 74

flattens array and returns as true/false to the given condition m1d = np.arange(12) print(m1d) log = m1d < 10 print(log) m1d[log] ^indexes, returning: array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) if print(m1d[log] is called, [0 1 2 3 4 5 6 7 8 9]

Question 75

reshape

Answer 75

x.reshape(shape)

Question 76

transpose

Answer 76

x.T swaps rows and columns

Question 77

ravel

Answer 77

x.ravel() returns flattened

Question 78

sum vs. np.sum

Answer 78

np.sum returns a single value