Python 3

Question 1

How to comment in Python?

Answer 1

#

Question 2

How to print in Python?

Answer 2

print(text here)

Question 3

Float number

Answer 3

Number with a decimal

Question 4

How to do exponents?

Answer 4

**
Example: For 6², you would write 6**2

Question 5

How to make a multiline string?

Answer 5

””” or ‘’’

Question 6

How to assign a variable to user input?

Answer 6

input(text here)

Question 7

Boolean operators in Python

Answer 7

and, or, not

Question 8

Else if statement

Answer 8

elif

Question 9

Syntax Error

Answer 9

Error caused by not following the proper syntax of the language

Question 10

Name Error

Answer 10

Error caused when an unknown variable is used

Question 11

Type Error

Answer 11

Error caused when you do an operation on an incorrect type

Question 12

how to concatanate Strings with ints or doubles

Answer 12

use a comma instead of a plus sign

Question 13

How to create a list

Answer 13

variable = [stuff here, separated by commas]

Question 14

True or False: Lists can contain any data type

Answer 14

True

Question 15

How to add something to the end of a list?

Answer 15

list.append(“”)

Question 16

list concatination

Answer 16

use the + symbol and store it in a new list

Question 17

How to access the last element of a list

Answer 17

use -1 (-2 would access second to last, etc.)

Question 18

How to add an element to a specific index in a list?

Answer 18

.insert(index, element)

Question 19

How to remove an element by index

Answer 19

.pop(index)
you can also do .pop() with no parameters and it will remove the last index

Question 20

what does range() do

Answer 20

range(10)
will create a range object with numbers 0 -> 9
range(2, 9)
will create a range object with numbers 2 -> 8
range(2, 9, 2)
will create a range object where each number is 2 greater than the previous
[2, 4, 6, 8]
note: because it is a range object, you need to convert it into a list using list(my_range)

Question 21

how to find the number of items in a list

Answer 21

len(my_list)

Question 22

how to slice a list

Answer 22

list_name[first index:last index]
note: it goes up to but not including last index

Question 23

what does list[:n] do?

Answer 23

selects the first n objects in a list (also works for negative, list[-n:] will select that last n objects in a list

Question 24

.count() method

Answer 24

will count the amount of times the parameter appears in a list (can also be used with 2d lists)

Question 25

.sort() method

Answer 25

will sort a list by numerical or alphabetical orders

Question 26

how to sort a list in reverse order

Answer 26

.sort(reverse=True)

Question 27

what is a tuple?

Answer 27

a data structure in python that allows us to store multiple pieces of data inside of it. similar to a list except that it is inmutable

Question 28

how to make a tuple

Answer 28

use () instead of []

Question 29

unpacking a tuple

Answer 29

you can use a tuple to set lots of variables with one line
example:
my_info = (‘mike’, 24, ‘programmer’
name, age, occupation = my_info

it will create three different variables, each assigned to the relative index of the tuple

Question 30

how to create a one element tuple

Answer 30

you MUST include a comma, or else it is just a regular data type
example:
WRONG -> one_element_tuple = (4)
RIGHT -> one_element_tuple = (4,)

Question 31

how to use the zip() function

Answer 31

• use it to combine 1D lists into 2D lists
  names_and_heights = zip(names, heights)
  note: will create a zip object, need to cast as a list using list(names_and_heights) to print
• also, inner lists will become tuples

Question 32

for loop strucure

Answer 32

for <temporary> in <list></list></temporary>

<action>
</action>

Question 33

elegant for loop

Answer 33

for ingredient in ingredients: print(ingredient)
(a one line loop)

Question 34

how to use range in for loops

Answer 34

Allows you to perform an action multiple times
(like loops in java)
for temp in range(6)

Question 35

continue statement

Answer 35

will stop the current iteration of the loop, move on to the next one

Question 36

list comprehensions

Answer 36

new_list = [<expression> for <element> in <collection>]
example: (will double each number in numbers)
numbers = [2, -1, 79, 33, -45]
doubled = [num * 2 for num in numbers]
print(doubled)</collection></element></expression>