---
title: Drill 12 Solution
tags: Drills-F20, 2020
---

# Drill 12 Solution

## Question 1
Given this function:

def if_statement(a, b):
    c = 10
    d = 10
    if (a < 5):
        c = 4
        d = 3
    else:
        if (b > 3):
            c = 5
            d = 5

    return c + d

What will the function return given the arguments 5 for a and 5 for b?

( ) 7
( ) 10
( ) 20
( ) 14

::: spoiler Answer
10

Unlike Pyret, where you used if-expressions, in Python you can create if-statements. The difference is that in Pyret, an if-expression needed to evaluate to a single value, whereas in Python, an if-statement just checks if a given condition is true or false and runs the appropriate code.

:::

## Question 2

Fill in the blanks for this Python function such that it returns the string "hello Professor Kathi".

 [Blank1] function(name):
    a = "[Blank2]"
    b = " Professor "
    [Blank3] a + [Blank4] + name

function([Blank5])

::: spoiler Answer

Blank1: `def`

Blank2: `hello`

Blank3: `return`

Blank4: `b`

Blank5: `"Kathi"`

In Pyret, every function evaluates to a certain value. In Python, if you want a function to return a piece of data you need to explicitly write return.

:::

## Question 3
Given this code:

a = 5
b = 9
c = 4
a = b

What is the value of the variable a?

( ) Python throws an error-- data is immutable and cannot be changed.
( ) Python throws an error-- the name b cannot be the value of a.
( ) 5
( ) 9

::: spoiler Answer
9

Python makes use of variables-- names of data that can be reassigned and mutated.

:::

## Question 4
Given this list of letters,

letters = ['a', 'b', 'c']

Fill in the blank to add the string 'd' to letters:

letters.________('d')

:::spoiler Answer
append

The list method append adds a piece of data to the end of a list.

:::

## Question 5
Given this list of letters:

letters = ['a', 'b', 'c']

Which of the following lines of code correctly gets 'b' from the list?

( ) `letters['b']`
( ) `letters[2]`
( ) `letters.get('b')`
( ) `letters[1]`

:::spoiler Answer
`letters[1]`

To access the data from a list at index i, write list[i]

:::