打印寫入CSV文件的行數

Question

[Python3]我有一個腳本讀取（長）CSV文件，包含電子郵件地址和相應的國家/地區代碼，並按國家/地區代碼拆分。 這很好，但我希望腳本根據每個文件打印出行數（即電子郵件）（已寫入）。

此外，我是編程和Python的新手，所以我很高興收到任何優化建議或其他一般提示！

輸入文件看起來像這樣：

12345@12345.com     us
xyz@xyz.com         gb
aasdj@ajsdf.com     fr
askdl@kjasdf.com    de
sdlfj@aejf.com      nl
...                 ...

輸出應該如下所示：

Done!
us: 20000
gb: 20000
de: 10000
fr: 10000
nl: 10000
...

我的代碼如下：

import csv, datetime
from collections import defaultdict

"""
Script splits a (long) list of email addresses with associated country codes by country codes.
Input file should have only two columns of data - ideally.
"""

# Declaring variables
emails = defaultdict(list)
in_file = "test.tsv"          # Write filename here.
filename = in_file.split(".")

"""Checks if file is comma or tab separated and sets delimiter variable."""
if filename[1] == "csv":
    delimiter = ','
elif filename[1] == "tsv":
    delimiter = '\t'

"""Reads csv/tsv file and cleans email addresses."""
with open(in_file, 'r') as f:
    reader = csv.reader(f, delimiter=delimiter)
    for row in reader:
        # Gets rid of empty rows
        if row:
            # Gets rid of non-emails
            if '@' in row[0]:
                # Strips the emails from whitespace and appends to the 'emails' list
                # Also now 'cc' is in the first position [0] and email in the second [1]
                emails[row[1].strip()].append(row[0].strip()+'\n')

""""Outputs the emails by cc and names the file."""
for key, value in emails.items():
    # Key is 'cc' and value is 'email'
    # File is named by "today's date-original file's name-cc"
    with open('{0:%Y%m%d}-{1}-{2}.csv'.format(datetime.datetime.now(), filename[0], key), 'w') as f:
        f.writelines(value)

Answer 1

要獲得您想要的輸出，您需要打印密鑰（您的國家/地區代碼）和值的長度（您的電子郵件列表），如下所示：

""""Outputs the emails by cc and names the file."""
for key, value in emails.items():
    # Key is 'cc' and value is 'email'
    # File is named by "today's date-original file's name-cc"
    with open('{0:%Y%m%d}-{1}-{2}.csv'.format(datetime.datetime.now(), filename[0], key), 'w') as f:
        f.writelines(value)

    # The file is closed (de-indented from the with), but we're still in the for loop
    # Use the format() method of a string to print in the form `cc: number of emails`
    print(`{}: {}`.format(key, len(value)))

這使用format()來創建一個像gb: 30000這樣的字符串（ 更多用法示例 ）。