发送带有数据框的电子邮件作为附件

Question

我正在尝试创建一个可以发送电子邮件的功能，该电子邮件带有作为 csv 文件附加的数据框。附加文件通常需要先将文件保存到磁盘，所以我不知道是否有任何直接的方法可以解决这个问题？

我已经创建了一个可以将数据帧附加为 HTML 的函数，还有一个可以将附件作为电子邮件发送的函数，但是没有可以直接将数据帧作为附件发送的函数

常规设置

from email.mime.application import MIMEApplication
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
import smtplib
import os
_server = 'MY_SERVER'
_port = 9999
_sender = 'my.email@domain.com'

def create_simple_mail(to, title):
    mail = MIMEMultipart()
    mail['Subject'] = title
    mail['To'] = to
    mail['From'] = _sender

发送数据帧为html

def mail_dataframe_as_html(to, msg, title, df):
    mail = create_simple_mail(to, msg, title)
    html_str = msg
    html_str += '<tr></tr><tr></tr>'
    html_str += df.to_html()
    mail.attach(MIMEText(html_str, 'html'))
    smtp_connection = smtplib.SMTP(_server, _port, timeout=120)
    smtp_connection.sendmail(_sender, to, mail.as_string())

发送附件

def attach_file_to_mail(mail,f):
    with open(f, "rb") as fil:
        part = MIMEApplication(fil.read(), Name=os.path.basename(f))
        part['Content-Disposition'] = 'attachment; filename="%s"' % os.path.basename(f)
        mail.attach(part)
    return mail

def mail_html(to, title, html, attachments=None):
    mail = create_simple_mail(to=to, msg=None, title=title)
    mail.attach(MIMEText(html, 'html'))
    if attachments is not None:
        for f in attachments:
            mail = attach_file_to_mail(mail,f)
    smtp_connection = smtplib.SMTP(_server, _port, timeout=120)
    smtp_connection.sendmail(_sender, to, mail.as_string())

Answer 1

试试 pandas.DataFrame.to_csv
示例。
发送带有 pandas 数据框的邮件作为 .csv 附件：

from email.mime.application import MIMEApplication
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
import smtplib
import os
import pandas as pd
from datetime import datetime

_server = 'smtp.example.com'
_port = 587
_sender = 'some_sender@example.com'
_pass = 'pass_value'

def create_simple_mail(to, title):
    mail = MIMEMultipart()
    mail['Subject'] = title
    mail['To'] = to
    mail['From'] = _sender
    return mail

def attach_file_to_mail(mail,f):
    with open(f, "rb") as fil:
        part = MIMEApplication(fil.read(), Name=os.path.basename(f))
        part['Content-Disposition'] = 'attachment; filename="%s"' % os.path.basename(f)
        mail.attach(part)
    return mail

def mail_html(to, title, html, attachments=None):
    mail = create_simple_mail(to=to, title=title)
    mail.attach(MIMEText(html, 'html'))
    if attachments is not None:
        for f in attachments:
            mail = attach_file_to_mail(mail,f)
    
    smtp_connection = smtplib.SMTP(_server, _port, timeout=120)
    

    # I tested with TLS server connection
    smtp_connection.ehlo()
    smtp_connection.starttls()
    smtp_connection.ehlo()
    smtp_connection.login(_sender, _pass)

    smtp_connection.sendmail(_sender, to, mail.as_string())


if __name__ == "__main__":

    df_data = {'num': [1, 2, 3],
        'name': ['some val 1','some val 2','some val 3'],
        'year': [2001, 2002, 2003],
        
        }

    df = pd.DataFrame(df_data, columns = ['num', 'name','year'])

    now = datetime.now() 
    date_time = now.strftime("%d_%m_%Y__%H_%M_%S")
    file_name = f'{date_time}.csv'
    df.to_csv(file_name, index = False)

    mail_html('some@example.com','Some title','<b>html text</b>',[file_name])

    # If need
    os.remove(file_name)

结果：

Answer 2

我想出了一个非常巧妙的解决方案，使用 __enter__ 和 __exit__ 来清理可以附加到电子邮件的临时生成文件。

import os
import uuid

class CreateAttachments:
    def __init__(self, dfs, file_names=None):
        self._attachments = dfs

        # Create generic file names if none was specified
        if file_names is None:
            self._names = [f'attached_df{i}.csv' for i in range(len(dfs))]

        # Ensure all file names ends with the .csv extension
        else:
            self._names = [fn if fn.endswith('.csv') else fn + '.csv' for fn in file_names]

            # If less file names than attachments were provided, generic names are appended
            if len(self._names) < len(self._attachments):
                self._names += [f'attached_df{i}.csv' for i in range(len(self._attachments) - len(self._names))]

        # Create a temporary folder for the files
        self._file_location = 'C:/Users/%s/%s/' % (os.getenv('username'), str(uuid.uuid4()))

    def __enter__(self):
        # If by the odd chance the temporary folder already exists, we abort the program
        if os.path.isdir(self._file_location):
            raise IsADirectoryError("Directory already exists. Aborting")

        # Create temporary folder
        os.makedirs(self._file_location)

        # For each attachment, save the dataframe to a .csv in the temporary folder
        attach_paths = []
        for attach, name in zip(self._attachments, self._names):
            tmp_path = self._file_location + name
            attach.to_csv(tmp_path)
            attach_paths.append(tmp_path)
        
        # Save all paths to class, as they are needed in the __exit__ function
        self.paths = attach_paths
        
        # Return paths to use for attachments
        return self.paths

    def __exit__(self, exc_type, exc_val, exc_tb):
        # Remove the .csv files for each attachment
        for path in self.paths:
            os.remove(path)
        
        # Remove the temporary folder
        os.removedirs(self._file_location)

使用上面的代码，我现在可以像这样创建附件：

import pandas as pd

df1 = pd.DataFrame([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
df2 = pd.DataFrame([[2, 4, 6], [3, 6, 9], [4, 8, 12]])

html_str = '''<table style="width:100%">'''
html_str += '<tr> <font size="4"><b>Some HTML example</b> </font size> </tr>'
html_str += '<br> This is a test mail.'
with CreateAttachments([df1, df2]) as f:
    mail_html(to='receiver@domain.com',
              html=html_str,
              title='Test email with attachments',
              attachments=f)

发送带有数据框的电子邮件作为附件

Sending email with dataframe as an attached file

python

pandas

email

smtp

mime