General python

Question 1

How do you get a new blank row into code?

Answer 1

\n , print()

Question 2

What is the escape character?

Answer 2

\

Question 3

What does \ do?

Answer 3

Announces that the string should be paused and that the character after means something

Question 4

How do you print the character \

Answer 4

print(“\”)

Question 5

What happens when you pass muliple arguments to a print function

Answer 5

1) It combines them all on one line

2) It puts a small between the outputted arguments

Question 6

What is a positional argment?

Answer 6

The location determines what it does

Question 7

How do you use keyword arguments?

Answer 7

1) keyword = value

2) after positional arguments

Question 8

What does the default end keywork argument do in print

Answer 8

\n

Question 9

How do you alter the default behaviour of print to insert a space between arguments?

Answer 9

sep =

Question 10

What is a literal?

Answer 10

Data you can determine the value of without any additional knowledge e.g. 123 vs c

Question 11

What are the 2 ways to show quotation marks in Python

Answer 11

" or use ‘’ instead of “”

Question 12

How do you encode ‘to the power of’

Answer 12

**

Question 13

What does print(6/2) give you?

Answer 13

A float

Question 14

What does // do?

Answer 14

Integer division

Question 15

What happens when the result of // is not an integer?

Answer 15

Rounds to the lower number (ie. floor division)

Question 16

What is the result of print( 6 // - 4)?

Answer 16

-2

Question 17

What type does the % operation result in?

Answer 17

Float

Question 18

what is a unary and a binary operatory

Answer 18

Binary expect 2 arguments, unary expects 1

Question 19

Is python predominantly right side or left side binding?

Answer 19

Left side

Question 20

What is the exception to left side binding

Answer 20

Exponentiation

Question 21

What is the order of priority of operators?

Answer 21

1) + - (unary)
2) **
3) * / %
4) + - (binary)
5) , >=
6) ==, !=

Question 22

What does a variable contain?

Answer 22

A name and value

Question 23

How do you evaluate the square root of something?

Answer 23

** 0.5

Question 24

What does input() store values as?

Answer 24

A string

Question 25

What do you need to do to get input usable with operators?

Answer 25

float()

Question 26

What does isna() return?

Answer 26

Boolean series

Question 27

How do you count how many missing values?

Answer 27

df.isna().sum()

Question 28

How do you get a dataframe into a list?

Answer 28

df.values.flatten()

Question 29

How do you get summary statistics by row?

Answer 29

1) data = pd.DataFrame()
2) var = df.mean(axis = 1)
3) data[‘var’] = var

Question 30

What is the keyboard shortcut to see all methods?

Answer 30

tab after the .

Question 31

What is the keyboard shortcut to see the arguments available?

Answer 31

shift and tab

Question 32

What is the difference between a method and an attribute?

Answer 32

Attribute describes and has no parentheses, methods have parentheses

Question 33

Describe ==

Answer 33

Binary, left binded

Question 34

In python what are the comparison operators?

Answer 34

==, !=, >, =, <=

Question 35

What has higher priority: == or >=

Answer 35

> =

Question 36

What is the difference between if and elif?

Answer 36

If will always be evaluated, elif and else stop once something is found to be true (and assumes the previous thing was false)

Question 37

What does range(100) do?

Answer 37

0 to 99

Question 38

What does range(2,8) do?

Answer 38

2 to 7

Question 39

What does range(2,8,3)

Answer 39

2, 5

Question 40

What does break do?

Answer 40

Exits the loop immediately

Question 41

What does continue do?

Answer 41

Behaves as if the programme has reached the end of the body of the loop and starts the next turn

Question 42

What is the difference between break and continue?

Answer 42

Break exits the loop, continue goes to start the next loop immediately

Question 43

What are the logical operators?

Answer 43

and
or
not

Question 44

What are the logical operators vs the comparison operators?

Answer 44

Comparison >= > !=

Logical and or not

Question 45

What has higher priority; comparison operators or logical?

Answer 45

Comparison

Question 46

Is and binary or unary?

Answer 46

binary

Question 47

What has higher priority; and or or?

Answer 47

and

Question 48

What does not do?

Answer 48

It turns false into true and true into false?

Question 49

What priority is not equivalent to?

Answer 49

unary + and -

Question 50

What are the bitwise operators?

Answer 50

& | ~ ^

Question 51

Which are the logical operators and which are the bitwise operators?

Answer 51

Logical: and, or, not
Bitwise: & | ~ ^

Question 52

What is the difference between | and ~ ?

Answer 52

needs at least 1 1 - ~ needs exactly 1 1

Question 53

Do bitwise operators need integers or flats?

Answer 53

integers

Question 54

If a variable is 5, is it true or false?

Answer 54

True - anything that is not zero is true

Question 55

What is the difference between logical and bitwise operations?

Answer 55

Bitwise takes the bit representation of the number and then compares each pair of bits separately

Question 56

How do you use an abbreviated form of bitwise operators?

Answer 56

x = x & y is x &= y

Question 57

How do you replace an item in a list?

Answer 57

listname[index value] = newvalue

Question 58

what is del?

Answer 58

and instruction not a funcction

Question 59

how do you get the last item in the list?

Answer 59

list[-1]

Question 60

What is a method versus a function?

Answer 60

A method is a kind of function but it is owned by the data it works for and can change the internal state of the data

Question 61

How do you add to a list?

Answer 61

Append (adds to the end)

Insert (you specific the location, and everything moves to the right)

Question 62

Can you use list[new index] to add to a lits?

Answer 62

no

Question 63

How do you use a for loop to add up all items in a list?

Answer 63

list = [1,2,3,4,5]
total = 0

for i in list:
total += i

print(total)

Question 64

How do you swap the variables in a list?

Answer 64

var1 = 4
var2 = 6

var1, var2 = var2, var1

Question 65

Is a list ordered or unordered?

Answer 65

Ordered

Question 66

Where does mylist[:end] start?

Answer 66

0

Question 67

How do you copy the full list?

Answer 67

mylist[:]

Question 68

How do you remove some items of a list?

Answer 68

del mylist[:4]

Question 69

Does using del create a new list?

Answer 69

no

Question 70

How do you delete a list contents?

Answer 70

del mylist[:]

Question 71

How do you delete a list?

Answer 71

del mylist

Question 72

How do you work out if something is in a list?

Answer 72

in or not in

Question 73

What is the difference between:
list2 = list1
list2 = list1[:]

Answer 73

The second copies the contents, the first points to the location of list 1 so if you change list it is refleccted

Question 74

Where do funcitons come from?

Answer 74

Python (built in), modules, code

Question 75

What is special about a parameter?

Answer 75

It only exists inside a function

Assigning a value to it only happens specifying an argument when invoking the function

Question 76

Can a variable and a parameter be named the same?

Answer 76

Yes

Question 77

What are the ways ways to pass parameters?

Answer 77

Positional and keyword

Question 78

How do you get a function to insert default value for a parameter?

Answer 78

def function(keyword = ‘default’)

Question 79

Can you overwrite a default parameter in a function?

Answer 79

Yes

Question 80

What comes first, positional or keyword arguments?

Answer 80

Positional

Question 81

How many types of return are there?

Answer 81

Return without an expression

Return with an expression

Question 82

What does return without an expression do?

Answer 82

Stop the funcions activity on demand and return to the point of invocation

Question 83

What does return with an expression do?

Answer 83

Stops the functions execution and then evaluates the expression’s value and return the functions result

Question 84

What is return with an expression

Answer 84

Something after the return instruction

Question 85

What must you do to see the return with an expressions results?

Answer 85

Assign it to a variable and print it

Question 86

What is None?

Answer 86

A keyword?

Question 87

What happens when a function doesn’t return a certain value using return with an expression?

Answer 87

Returns None

Question 88

Can you pass a list to a function?

Answer 88

Yes

Question 89

How does insert work?

Answer 89

Add an item to the list at a specific value list.insert(0,i)

Question 90

Does a variable defined outside the body of a function exist inside?

Answer 90

Yes

Question 91

What is the exception to a variable being read from outside the function?

Answer 91

A variable existing outside a function has a scope inside the functions’ bodies, excluding those of them which define a variable of the same name.

Question 92

Does a function receive an argument or an arguments value?

Answer 92

Arguments value

Question 93

Can you change a paramters value?

Answer 93

Yes

Question 94

True or false: A variable that exists outside a function has a scope inside the function body

Answer 94

True

Question 95

True or false: A variable that exists outside a function does not have scope inside the function body

Answer 95

False

Question 96

How do you get a variable to be applicable outside a functions body?

Answer 96

global var

Question 97

What is mutable and immutable data?

Answer 97

Immutable cannot be chnaged

Question 98

What is a sequence?

Answer 98

A sequence type is a type of data in Python which is able to store more than one value (or less than one, as a sequence may be empty), and these values can be sequentially (hence the name) browsed, element by element.

Question 99

What is the syntax for a tuple?

Answer 99

tuple1 = (1, 2, 4, 8)
tuple2 = 1., .5, .25, .125

Question 100

If you print:
tuple1 = (1, 2, 4, 8)
tuple2 = 1., .5, .25, .125
What do you see?

Answer 100

(1, 2, 4, 8)

1.0, 0.5, 0.25, 0.125

Question 101

Can tuple elements be of different types?

Answer 101

Yes. a tuple’s elements can be variables, not only literals. Moreover, they can be expressions if they’re on the right side of the assignment operator.

Question 102

Can a tuple be empty?

Answer 102

Yes

Question 103

How do you create an empty tuple?

Answer 103

emptyTuple = ()

Question 104

What do you have to do to create a one element tuple?

Answer 104

oneElementTuple1 = (1, )
oneElementTuple2 = 1., 

Add a comma to distinguish it from single value

Question 105

What happens if you + tuples together?

Answer 105

It joins them together

Question 106

What happens if you * a tuple?

Answer 106

It multiples them

Question 107

What works on tuples?

Answer 107

len()
+
*
In and not in

Question 108

Is a dictionary a sequence?

Answer 108

No

Question 109

Is a dictionary mutable?

Answer 109

yes

Question 110

What is a dictionary?

Answer 110

This means that a dictionary is a set of key-value pairs.

Question 111

Keys in a dictionary can be the same: T or F?

Answer 111

False

Question 112

What kinds of data can be in dictionary/

Answer 112

Anything except lists

Question 113

What do len for a dictionary give you?

Answer 113

The number of key-value elements

Question 114

What is a dictinoary syntax?

Answer 114

dictionary = {“cat” : “chat”, “dog” : “chien”, “horse” : “cheval”}
The list of pairs is surrounded by curly braces, while the pairs themselves are separated by commas, and the keys and values by colons.

Question 115

Is a dictionary ordered or unordered?

Answer 115

Unordered

Question 116

Are keys in a dictionary case sensitive or not?

Answer 116

Yes

Question 117

Can you use a for loop on a dictionary?

Answer 117

No

Question 118

How can you get a for loop to work on on dictionary?

Answer 118

The first of them is a method named keys(), possessed by each dictionary. The method returns an iterable object consisting of all the keys gathered within the dictionary. Having a group of keys enables you to access the whole dictionary in an easy and handy way.

Question 119

How do you extract bits out of dictionaries?

Answer 119

.items()
.values()
.keys()

Question 120

What data types does dict.items() return?

Answer 120

A tuple

Question 121

How do you replace a value within a dictionary?

Answer 121

dict[‘key’] = ‘new value’

Question 122

How do you add a new key, value pair to a dictionary?

Answer 122

dict[‘new key’] = ‘value’
or
dict.update({‘duck’: ‘canard’})

Question 123

With lists can you assign a value to a non existnent index?

Answer 123

No

Question 124

How do you remove a key from a dictionary?

Answer 124

del dict[‘key’]

Question 125

What can you do to edit a dictionary?

Answer 125

Update values - dict[‘original’] = ‘new’
Add new values dict[‘new key’]
Delete - del dict[‘key’]

Question 126

How can items be added to a list?

Answer 126

Append - if a list, adds the list to the list

Extend - adds individual elements

Question 127

How do you create a tuple?

Answer 127

(1,2,3)

Question 128

How do you create a one element tuple?

Answer 128

(1,) with a comma otherwise a variable is created

Question 129

Can you access elements of a tuple by indexing?

Answer 129

Yes

Question 130

How do you create an empty tuple?

Answer 130

()

Question 131

What are tuples?

Answer 131

Immutable and ordered/

Question 132

Can you iterate over a tuple?

Answer 132

Yes

Question 133

How do you work out if something is in a tuple?

Answer 133

print( 5 in tup)

in or not in

Question 134

Can you join or mutliple tuples?

Answer 134

Yes

Question 135

How do you convert an existing element to a tuple?

Answer 135

tuple(lst)

Question 136

How do you iterate over a dictionary?

Answer 136

for keys, values in dict1.items():

print(keys, values)

Question 137

What can you do to check if a key is in a dictionary?

Answer 137

if “key” in dict:

print(“yes”)

Question 138

How do you delete an item from a dicctionary?

Answer 138

del dict1[‘key1’]

Question 139

What is the difference between clear and delete for dictionary/

Answer 139

clear removes the items, delete actually gets rid of it

Question 140

How do you create a dictionary from another data type?

Answer 140

dict()

Question 141

How do you make range go negative

Answer 141

You must specify the last argument to be -1 otherwise it won’t work

Question 142

What data type do you get from this?

tup[0:3]

Answer 142

Tuple

Question 143

What data type do you get from this?
tup = (1,2,3)
tup[1]

Answer 143

integer

Question 144

Why is this bad? From math import *

Answer 144

Because every function is brought into the glboal scope and could conflict with your variables

Question 145

What does from maths import mean enable you to do?

Answer 145

Use mean() without having to do maths.mean()

Question 146

Is a tuple immutable?

Answer 146

Yes but you can overrite it - it points to a new object

Question 147

How do you get the unique refence of an object?

Answer 147

Id()

Question 148

Do you need () for a tupe?

Answer 148

No

Question 149

How do you create a single item tuple?

Answer 149

(‘Red’,)

Question 150

Tuple or string? (‘Red’)

Answer 150

String - for it to be a tuple it would have to be (‘Red’,)

Question 151

How do you access elements of a tuple?

Answer 151

Square brackets - just like lists

Question 152

Tuple1 = (10,20,30). Is tuple1 the object or is (10,20,30)?

Answer 152

(10,20,30) is the object

Question 153

Tuple1 = (10,20,30) and then tuple 2 = Tuple 2. If you then modify Tuple1, does tuple 2 change?

Answer 153

No because tuples are immutable. MOdifying tuple1 creates a new object whereas tuple2 points to the original object

Question 154

If you append a tuple to a list what happens?

Answer 154

The nubmers are added to to the end of the list (as a list)

Question 155

Can tuples have mutable objects?

Answer 155

Yes (1,2,[‘hello’, ‘bye’])

Question 156

If you modify a mutable oject within a tuple, does it create a new object?

Answer 156

No

Question 157

How do you unpack the tuple?

Answer 157

x, y = (‘Amanda’,[1,2,3])

Question 158

What does enumerate do?

Answer 158

Products a sequence of tuples with the index and item of the list.

Question 159

How do you get an output like this?

0: red
1: white
3: blue

Answer 159

for index,value in enumerate([‘red’,’white’,’blue’]):

print(f’{index}: {value}’)

Question 160

How do you delete items from a list?

Answer 160

del numbers[-1]

Question 161

Using del - can you delete items from a list, a whole variable or both?

Answer 161

Both

Question 162

How do you select every other item from a list?

Answer 162

ls[::2]

Question 163

Sorted() or ls.sort(). One is method one is a fuction, which way around?

Answer 163

Sorted is a built in function, sort is method

Question 164

ls.sort() - does it happen in place?

Answer 164

Yes

Question 165

Can you use sorted() on immuatable types?

Answer 165

Yes but you have to assign it to a new variable name

Question 166

Sorted() vs ls.sort() which one is in place?

Answer 166

ls.sort() is in place

Question 167

What happens if you mix caps and non caps when sorting?

Answer 167

It might not come alphabetically as items are sorted lexigraphically

Question 168

How do you find the location within an item in a list?

Answer 168

list.index(5)

Question 169

What do you use to evaluation if something is contained in a list?

Answer 169

in
1000 in numbers
False

Question 170

How do you generate a list using rangewithout using append?

Answer 170

list comprehension

list = [i for i in range(0,6)

Question 171

How do you generate a list only if certain conditions are met

Answer 171

list = [i for i in range(0,6) if i % 2 != 0]

Question 172

What is the difference between list comprehension and generator expressions?

Answer 172

List comprehension is greedy - it means that the output has to be generated immediately. Genetaor expressions us lazy evaluation - values are produced on demand
List is []
Generator is ()

Question 173

what is filter?

Answer 173

An inbuilt higher order function (can take other functions)

Question 174

How do you use filter?

Answer 174

list(filter(somefunction, the item to filter)

The somefunction can either be a function name or lambda e.g.

List(filter(lambda x : ( x > 4 ) == True, somelist)

Question 175

What is the structure of a lambda expression?

Answer 175

lamba x: x % 2 != 0

Question 176

Do map and filter actually return the sequences of elements?

Answer 176

No it returns an iterator - you have to iterate over the object to get the sequence of values. list() does this

Question 177

When do you use map versus filter?

Answer 177

Map when you want to do something to every element, filter when you want to filter on the elements

Question 178

What does zip do?

Answer 178

Combines parts of different lists / tuples

Question 179

If you create a list of lists - do the rows have to have the same number of columns?

Answer 179

No - jagged array

Question 180

If you want to index a multidimensional list, what comes first row or column?

Answer 180

Row

Question 181

How do you index a multidimensional list? a[1,2] or a[1][2]

Answer 181

a[1][2]

Question 182

Can the keys of a dictionary be mutable?

Answer 182

No

Question 183

What does len of a dictionary reveal?

Answer 183

The number of key value pairs

Question 184

What is the difference between del x and x.clear()

Answer 184

Del removes the variable name, clear keeps the variable name

Question 185

What does dictionary.items() give you?

Answer 185

An iterator which you can iterate over - gives a tuple of key value pairs

Question 186

Is a dictionary mutable?

Answer 186

Yes

Question 187

How do you add a new dicitonary key value pair?

Answer 187

dict[‘new label’]

Question 188

What order does the dictionary show?

Answer 188

The order they were added

Question 189

How do you remove an element from a dictionary?

Answer 189

del dict[‘element’]

Question 190

When you in to search for an item in a dictionary - does it look at keys, values or both?

Answer 190

keys

Question 191

What is the opposite of in

Answer 191

Not in

Question 192

What does this do? print(i, end = ‘ ‘)

Answer 192

Prints items on one line with a space between

Question 193

What can you use to act as a word counter?

Answer 193

from collections import Counter

Question 194

How can you update a dctionary on mass

Answer 194

dictionary.update({})

Question 195

dictionary.update({}) or dictionary update(key = value)

Answer 195

Either works

Question 196

Can you pass a tuple to dictionary.update?

Answer 196

Yes

Question 197

What is the difference between a set and dictionary?

Answer 197

{} but not key value pair in set. Items in sets are not in the order they are inserted in

Question 198

Can you have duplicates in a set?

Answer 198

No

Question 199

How do you create a set?

Answer 199

{} with a sequence of values or set()

Question 200

How do you create an empty set?

Answer 200

set(), {} won’t work

Question 201

Are sets mutable or immutable?

Answer 201

Mutable but there is a frozen set which is immutable

Question 202

When comparing sets, does the order of the items matter?

Answer 202

No

Question 203

What does < do when comparing sets?

Answer 203

Tests if it is sub set

Question 204

What will this output? {1,2,3}

Answer 204

False, there must be fewer elements in the left hand one

Question 205

What is the difference between < and issubset()?

Answer 205

issubset() will evaluate to true if the sets are equal

Question 206

How do you merge 2 sets?

Answer 206

or union()

Question 207

How do you return only the overlapping items between 2 sets?

Answer 207

& or intersection()

Question 208

How do you get items that are only in one set (the left one)

Answer 208

• or difference()

Question 209

How do you get the items that are not common across both sets?

Answer 209

^ or symmetric_difference

Question 210

How can you change elements in set?

Answer 210

.add() .remove()

Question 211

What is the structure to use map?

Answer 211

List(map(lambda x: x*2, thelist))

Question 212

Can you use map() or do you need to do something else?

Answer 212

It produces something you can iterate over so you need to use list()