Why my code gets complaint?

In Cleaning and Preparing Data in Python Practice Problems: question 5, I have the code below. But it complains “File listings_clean.csv does not have the expected content.” From print out, I don’t see anything different from the answer.

Screen Link:

My Code:

import csv

def write_csv(rows):
    f = open('listings_clean.csv', mode='w')
    writer = csv.writer(f)
    for row in rows:
        writer.writerow(row)
    f.close()

# Write your code below
def clean_available_col():
    f = open('listings.csv',mode='r')
    reader=csv.reader(f)
    rows=list(reader)[1:]
    dic={'Y':'yes','y':'yes','NO':'no','n':'no'}
    for row in rows:
        if row[3] in dic:
            row[3]=dic[row[3]]
        print(row)
    write_csv(rows)

clean_available_col()
f=open('listings_clean.csv',mode='r')
reader=csv.reader(f)
rows = list(reader)
for i in range(8):
    print(rows[i])
        

What I expected to happen:

What actually happened:

Replace this line with the output/error

Hello @shi.aaron,

The bug is here:

Although your code will give the correct answer, the clean_available_col function will always remove the first row of the listings_clean.csv file when it is called.
This is the reason for the complaints.

rows=list(reader) should work fine for the grader.

Yes, I also figured out myself. Thanks pointing it out.