Python读取CSV生成一维邮箱列表的代码修正求助

Hey there! I see exactly what's going on here—let's get that nested list sorted out into the flat format you need.

The Problem #

When you use csv.reader, every row it returns is a list of values (even if your CSV only has one column). So when you do email_id.append(row), you're adding an entire sublist (like ['emailid1@xyz.com']) to your main list instead of just the email string itself.

You mentioned trying email_id.extend(row) and it didn't work—maybe you had a typo or placed it wrong? Let's walk through two solid solutions:

Solution 1: Use extend() instead of append() #

Since each row is a single-element list, extend() will unpack that list and add the email string directly to your main list:

import csv
email_id = []
with open('contacts1.csv', 'r') as file:
    reader = csv.reader(file, delimiter=',')
    for row in reader:
        email_id.extend(row)  # Unpacks the row list and adds the email string
print(email_id)

Solution 2: Access the first element of the row #

If you want to be explicit (great for readability, especially if you ever add more columns later), you can grab the first item in each row with row[0]:

import csv
email_id = []
with open('contacts1.csv', 'r') as file:
    reader = csv.reader(file, delimiter=',')
    for row in reader:
        # Make sure the row isn't empty before accessing index 0
        if row:
            email_id.append(row[0])
print(email_id)

I added a quick check for empty rows here to avoid index errors, which is a nice safety net if your CSV has any blank lines.

What the Output Will Look Like #

Either solution will give you the flat list you want:

['emailid1@xyz.com','emailid2@xyz.com','emailid3@xyz.com']

内容的提问来源于stack exchange，提问作者nomanahmedna