INSTRUCTIONS:

Examine the starter code in the editor window, and run the code in the interpreter.

The function extract$\_$even$\_$numbers$\_$in$\_$list extracts the elements of a list that are even. The list my$\_$evens has been created by calling this function on my$\_$list. Inspect the data in my$\_$evens.

Create a new list called my$\_$evens$2$ by using a list comprehension that does the same thing as extract$\_$even$\_$numbers$\_$in$\_$list, but all in one line.

The function extract$\_$digits$\_$from$\_$string extracts the characters in a string that are digits. In this function, the method string.is$\_$digit is used to test whether or not a string is a digit $($or collection of digits$).$ The list str$\_$digits has been created by calling this function on the supplied string s$.$ Inspect the data in str$\_$digits.

Create a new list called str$\_$digits$2$ by using a list comprehension that d

STARTER CODE:

my$\_$list $=[1,3,14,22,29,43,89,102,256]$

def extract$\_$even$\_$numbers$\_$in$\_$list$($alist$)$:

$"""$

Returns a list of the numbers in the input alist

that are even numbers

NOTE: n$\%2==0$ if n is even, n$\%2==1$ if n is odd

$"""$

result $=[]$

for elem in alist:

if elem$\%2==0$:

result.append$($elem$)$

return result

def extract$\_$digits$\_$from$\_$string$($s$)$:

$"""$

Returns a list of all the digits that appear in a string,

in the order in which they are encountered.

$"""$

result $=[]$

for c in s:

if c$.$isdigit$()$:

result.append$($c$)$

return result

def make$\_$dict$\_$of$\_$squares$($n$)$:

$"""$

Returns a dictionary that maps from integers to their squares,

starting with $0$ and ending at one less than the input n

$"""$

result $=\{\}$

for i in range$($n$)$:

result$[$i$]=$ i$*$i

return result

my$\_$evens $=$ extract$\_$even$\_$numbers$\_$in$\_$list$($my$\_$list$)$

s $=$ 'The answer is $42,$ but many people guess $12.\text{'}$

str$\_$digits $=$ extract$\_$digits$\_$from$\_$string$($s$)$

squares $=$ make$\_$dict$\_$of$\_$squares$(10)$