Why are we not creating a list for freq-table function

Q&A
#1

Screen Link:
Learn About Functions | Dataquest

My Code: 

def freq_table(n):
    a ={}
    x = extract(n)
    for c in x:
        if c in a:
            a[c] += 1
        else:
            a[c] = 1
    return a

What I expected to happen:
Expected the code to run

What actually happened:
It gave an error and apparently the main root cause is this line " x = extract(n)".
In the solution after creating an empty dictionary, why are we not creating a list with keys, just like we did earlier examples. Why is it that - creating a list is not required and instead immediately after the blank dictionary, the for- in code is referring to the parameter in the function ( i.e. def freq_table(column) , when we are yet to define the argument which will be in the form of list

Running your code caused an error.
genres_ft isn’t defined in your code, but we expected it to be dict type
#2

Please share all of your code here along with the full error. It’s unclear what the cause of the error actually is based on your current description.

#3

CODE FROM THE PREVIOUS SCREEN

opened_file = open(‘AppleStore.csv’)
from csv import reader
read_file = reader(opened_file)
apps_data = list(read_file)

def extract(index):
column =
for row in apps_data[1:]:
value = row[index]
column.append(value)
return column

genres = extract(11)

def freq_table(n):
a ={}
x = extract(n)
for c in x:
if c in a:
a[c] += 1
else:
a[c] = 1
return a

genres_ft = freq_table(genres)

#4

You are calling extract() inside your freq_table() function, even though it has already been called before -

freq_table function does not need to call the extract() function.

Because that’s what extract() function does for you. You are creating a frequency table based on the list that you get from calling the extract() function. The items in that list will be the keys for your frequency table.

I would recommend going over the instructions carefully once more to better understand what’s going on.

#5

thanks, i think it will take some time to build intuition. Or is that wrong to say in coding !
if a list has already been called earlier - extract () - it need not be called again even though that was the format in simpler examples . That’s something to dwell upon