通过gmail和python发送电子邮件

Question

推荐使用gmail和python发送电子邮件的方式是什么？

有很多这样的线程，但大多数都是旧的，而且带有用户名和密码的smtp不再工作，或者用户必须降低gmail的安全性（例如，请参见here）。

OAuth是推荐的方式吗？

Answer 1

下面是在没有附件（或有附件）的情况下发送电子邮件所需的Python3.6代码（和说明）。

（要与附件一起发送，只需取消注释下面的2行## without attachment，并注释下面的2行## with attachment）

阿帕达纳的所有功劳（和投票权）

import httplib2
import os
import oauth2client
from oauth2client import client, tools
import base64
from email import encoders

#needed for attachment
import smtplib  
import mimetypes
from email import encoders
from email.message import Message
from email.mime.audio import MIMEAudio
from email.mime.base import MIMEBase
from email.mime.image import MIMEImage
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication
#List of all mimetype per extension: http://help.dottoro.com/lapuadlp.php  or http://mime.ritey.com/

from apiclient import errors, discovery  #needed for gmail service




## About credentials
# There are 2 types of "credentials": 
#     the one created and downloaded from https://console.developers.google.com/apis/ (let's call it the client_id) 
#     the one that will be created from the downloaded client_id (let's call it credentials, it will be store in C:\Users\user\.credentials)


        #Getting the CLIENT_ID 
            # 1) enable the api you need on https://console.developers.google.com/apis/
            # 2) download the .json file (this is the CLIENT_ID)
            # 3) save the CLIENT_ID in same folder as your script.py 
            # 4) update the CLIENT_SECRET_FILE (in the code below) with the CLIENT_ID filename


        #Optional
        # If you don't change the permission ("scope"): 
            #the CLIENT_ID could be deleted after creating the credential (after the first run)

        # If you need to change the scope:
            # you will need the CLIENT_ID each time to create a new credential that contains the new scope.
            # Set a new credentials_path for the new credential (because it's another file)
def get_credentials():
    # If needed create folder for credential
    home_dir = os.path.expanduser('~') #>> C:\Users\Me
    credential_dir = os.path.join(home_dir, '.credentials') # >>C:\Users\Me\.credentials   (it's a folder)
    if not os.path.exists(credential_dir):
        os.makedirs(credential_dir)  #create folder if doesnt exist
    credential_path = os.path.join(credential_dir, 'cred send mail.json')

    #Store the credential
    store = oauth2client.file.Storage(credential_path)
    credentials = store.get()

    if not credentials or credentials.invalid:
        CLIENT_SECRET_FILE = 'client_id to send Gmail.json'
        APPLICATION_NAME = 'Gmail API Python Send Email'
        #The scope URL for read/write access to a user's calendar data  

        SCOPES = 'https://www.googleapis.com/auth/gmail.send'

        # Create a flow object. (it assists with OAuth 2.0 steps to get user authorization + credentials)
        flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
        flow.user_agent = APPLICATION_NAME

        credentials = tools.run_flow(flow, store)

    return credentials




## Get creds, prepare message and send it
def create_message_and_send(sender, to, subject,  message_text_plain, message_text_html, attached_file):
    credentials = get_credentials()

    # Create an httplib2.Http object to handle our HTTP requests, and authorize it using credentials.authorize()
    http = httplib2.Http()

    # http is the authorized httplib2.Http() 
    http = credentials.authorize(http)        #or: http = credentials.authorize(httplib2.Http())

    service = discovery.build('gmail', 'v1', http=http)

    ## without attachment
    message_without_attachment = create_message_without_attachment(sender, to, subject, message_text_html, message_text_plain)
    send_Message_without_attachment(service, "me", message_without_attachment, message_text_plain)


    ## with attachment
    # message_with_attachment = create_Message_with_attachment(sender, to, subject, message_text_plain, message_text_html, attached_file)
    # send_Message_with_attachment(service, "me", message_with_attachment, message_text_plain,attached_file)

def create_message_without_attachment (sender, to, subject, message_text_html, message_text_plain):
    #Create message container
    message = MIMEMultipart('alternative') # needed for both plain & HTML (the MIME type is multipart/alternative)
    message['Subject'] = subject
    message['From'] = sender
    message['To'] = to

    #Create the body of the message (a plain-text and an HTML version)
    message.attach(MIMEText(message_text_plain, 'plain'))
    message.attach(MIMEText(message_text_html, 'html'))

    raw_message_no_attachment = base64.urlsafe_b64encode(message.as_bytes())
    raw_message_no_attachment = raw_message_no_attachment.decode()
    body  = {'raw': raw_message_no_attachment}
    return body



def create_Message_with_attachment(sender, to, subject, message_text_plain, message_text_html, attached_file):
    """Create a message for an email.

    message_text: The text of the email message.
    attached_file: The path to the file to be attached.

    Returns:
    An object containing a base64url encoded email object.
    """

    ##An email is composed of 3 part :
        #part 1: create the message container using a dictionary { to, from, subject }
        #part 2: attach the message_text with .attach() (could be plain and/or html)
        #part 3(optional): an attachment added with .attach() 

    ## Part 1
    message = MIMEMultipart() #when alternative: no attach, but only plain_text
    message['to'] = to
    message['from'] = sender
    message['subject'] = subject

    ## Part 2   (the message_text)
    # The order count: the first (html) will be use for email, the second will be attached (unless you comment it)
    message.attach(MIMEText(message_text_html, 'html'))
    message.attach(MIMEText(message_text_plain, 'plain'))

    ## Part 3 (attachment) 
    # # to attach a text file you containing "test" you would do:
    # # message.attach(MIMEText("test", 'plain'))

    #-----About MimeTypes:
    # It tells gmail which application it should use to read the attachment (it acts like an extension for windows).
    # If you dont provide it, you just wont be able to read the attachment (eg. a text) within gmail. You'll have to download it to read it (windows will know how to read it with it's extension). 

    #-----3.1 get MimeType of attachment
        #option 1: if you want to attach the same file just specify it’s mime types

        #option 2: if you want to attach any file use mimetypes.guess_type(attached_file) 

    my_mimetype, encoding = mimetypes.guess_type(attached_file)

    # If the extension is not recognized it will return: (None, None)
    # If it's an .mp3, it will return: (audio/mp3, None) (None is for the encoding)
    #for unrecognized extension it set my_mimetypes to  'application/octet-stream' (so it won't return None again). 
    if my_mimetype is None or encoding is not None:
        my_mimetype = 'application/octet-stream' 


    main_type, sub_type = my_mimetype.split('/', 1)# split only at the first '/'
    # if my_mimetype is audio/mp3: main_type=audio sub_type=mp3

    #-----3.2  creating the attachment
        #you don't really "attach" the file but you attach a variable that contains the "binary content" of the file you want to attach

        #option 1: use MIMEBase for all my_mimetype (cf below)  - this is the easiest one to understand
        #option 2: use the specific MIME (ex for .mp3 = MIMEAudio)   - it's a shorcut version of MIMEBase

    #this part is used to tell how the file should be read and stored (r, or rb, etc.)
    if main_type == 'text':
        print("text")
        temp = open(attached_file, 'r')  # 'rb' will send this error: 'bytes' object has no attribute 'encode'
        attachment = MIMEText(temp.read(), _subtype=sub_type)
        temp.close()

    elif main_type == 'image':
        print("image")
        temp = open(attached_file, 'rb')
        attachment = MIMEImage(temp.read(), _subtype=sub_type)
        temp.close()

    elif main_type == 'audio':
        print("audio")
        temp = open(attached_file, 'rb')
        attachment = MIMEAudio(temp.read(), _subtype=sub_type)
        temp.close()            

    elif main_type == 'application' and sub_type == 'pdf':   
        temp = open(attached_file, 'rb')
        attachment = MIMEApplication(temp.read(), _subtype=sub_type)
        temp.close()

    else:                              
        attachment = MIMEBase(main_type, sub_type)
        temp = open(attached_file, 'rb')
        attachment.set_payload(temp.read())
        temp.close()

    #-----3.3 encode the attachment, add a header and attach it to the message
    # encoders.encode_base64(attachment)  #not needed (cf. randomfigure comment)
    #https://docs.python.org/3/library/email-examples.html

    filename = os.path.basename(attached_file)
    attachment.add_header('Content-Disposition', 'attachment', filename=filename) # name preview in email
    message.attach(attachment) 


    ## Part 4 encode the message (the message should be in bytes)
    message_as_bytes = message.as_bytes() # the message should converted from string to bytes.
    message_as_base64 = base64.urlsafe_b64encode(message_as_bytes) #encode in base64 (printable letters coding)
    raw = message_as_base64.decode()  # need to JSON serializable (no idea what does it means)
    return {'raw': raw} 



def send_Message_without_attachment(service, user_id, body, message_text_plain):
    try:
        message_sent = (service.users().messages().send(userId=user_id, body=body).execute())
        message_id = message_sent['id']
        # print(attached_file)
        print (f'Message sent (without attachment) \n\n Message Id: {message_id}\n\n Message:\n\n {message_text_plain}')
        # return body
    except errors.HttpError as error:
        print (f'An error occurred: {error}')




def send_Message_with_attachment(service, user_id, message_with_attachment, message_text_plain, attached_file):
    """Send an email message.

    Args:
    service: Authorized Gmail API service instance.
    user_id: User's email address. The special value "me" can be used to indicate the authenticated user.
    message: Message to be sent.

    Returns:
    Sent Message.
    """
    try:
        message_sent = (service.users().messages().send(userId=user_id, body=message_with_attachment).execute())
        message_id = message_sent['id']
        # print(attached_file)

        # return message_sent
    except errors.HttpError as error:
        print (f'An error occurred: {error}')


def main():
    to = "youremail@gmail.com"
    sender = "myemail@gmail.com"
    subject = "subject test1"
    message_text_html  = r'Hi<br/>Html <b>hello</b>'
    message_text_plain = "Hi\nPlain Email"
    attached_file = r'C:\Users\Me\Desktop\audio.m4a'
    create_message_and_send(sender, to, subject, message_text_plain, message_text_html, attached_file)


if __name__ == '__main__':
        main()

Answer 2

答案展示了如何使用gmail API和python发送电子邮件。还更新了发送电子邮件附件的答案。

Gmail API&；OAuth->；无需在脚本中保存用户名和密码。

脚本第一次打开浏览器授权脚本时，将在本地存储凭据（它不会存储用户名和密码）。后续运行不需要浏览器，可以直接发送电子邮件。

使用此方法，您将不会得到如下SMTPException之类的错误，并且不需要允许访问不太安全的应用程序：

raise SMTPException("SMTP AUTH extension not supported by server.")  
smtplib.SMTPException: SMTP AUTH extension not supported by server.

以下是使用gmail API发送电子邮件的步骤：

（向导链接here，更多信息here）

第2步：安装Google客户端库

pip install --upgrade google-api-python-client

第3步：使用以下脚本发送电子邮件（只需更改main函数中的变量）

import httplib2
import os
import oauth2client
from oauth2client import client, tools, file
import base64
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from apiclient import errors, discovery
import mimetypes
from email.mime.image import MIMEImage
from email.mime.audio import MIMEAudio
from email.mime.base import MIMEBase

SCOPES = 'https://www.googleapis.com/auth/gmail.send'
CLIENT_SECRET_FILE = 'client_secret.json'
APPLICATION_NAME = 'Gmail API Python Send Email'

def get_credentials():
    home_dir = os.path.expanduser('~')
    credential_dir = os.path.join(home_dir, '.credentials')
    if not os.path.exists(credential_dir):
        os.makedirs(credential_dir)
    credential_path = os.path.join(credential_dir,
                                   'gmail-python-email-send.json')
    store = oauth2client.file.Storage(credential_path)
    credentials = store.get()
    if not credentials or credentials.invalid:
        flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
        flow.user_agent = APPLICATION_NAME
        credentials = tools.run_flow(flow, store)
        print('Storing credentials to ' + credential_path)
    return credentials

def SendMessage(sender, to, subject, msgHtml, msgPlain, attachmentFile=None):
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    service = discovery.build('gmail', 'v1', http=http)
    if attachmentFile:
        message1 = createMessageWithAttachment(sender, to, subject, msgHtml, msgPlain, attachmentFile)
    else: 
        message1 = CreateMessageHtml(sender, to, subject, msgHtml, msgPlain)
    result = SendMessageInternal(service, "me", message1)
    return result

def SendMessageInternal(service, user_id, message):
    try:
        message = (service.users().messages().send(userId=user_id, body=message).execute())
        print('Message Id: %s' % message['id'])
        return message
    except errors.HttpError as error:
        print('An error occurred: %s' % error)
        return "Error"
    return "OK"

def CreateMessageHtml(sender, to, subject, msgHtml, msgPlain):
    msg = MIMEMultipart('alternative')
    msg['Subject'] = subject
    msg['From'] = sender
    msg['To'] = to
    msg.attach(MIMEText(msgPlain, 'plain'))
    msg.attach(MIMEText(msgHtml, 'html'))
    return {'raw': base64.urlsafe_b64encode(msg.as_string())}

def createMessageWithAttachment(
    sender, to, subject, msgHtml, msgPlain, attachmentFile):
    """Create a message for an email.

    Args:
      sender: Email address of the sender.
      to: Email address of the receiver.
      subject: The subject of the email message.
      msgHtml: Html message to be sent
      msgPlain: Alternative plain text message for older email clients          
      attachmentFile: The path to the file to be attached.

    Returns:
      An object containing a base64url encoded email object.
    """
    message = MIMEMultipart('mixed')
    message['to'] = to
    message['from'] = sender
    message['subject'] = subject

    messageA = MIMEMultipart('alternative')
    messageR = MIMEMultipart('related')

    messageR.attach(MIMEText(msgHtml, 'html'))
    messageA.attach(MIMEText(msgPlain, 'plain'))
    messageA.attach(messageR)

    message.attach(messageA)

    print("create_message_with_attachment: file: %s" % attachmentFile)
    content_type, encoding = mimetypes.guess_type(attachmentFile)

    if content_type is None or encoding is not None:
        content_type = 'application/octet-stream'
    main_type, sub_type = content_type.split('/', 1)
    if main_type == 'text':
        fp = open(attachmentFile, 'rb')
        msg = MIMEText(fp.read(), _subtype=sub_type)
        fp.close()
    elif main_type == 'image':
        fp = open(attachmentFile, 'rb')
        msg = MIMEImage(fp.read(), _subtype=sub_type)
        fp.close()
    elif main_type == 'audio':
        fp = open(attachmentFile, 'rb')
        msg = MIMEAudio(fp.read(), _subtype=sub_type)
        fp.close()
    else:
        fp = open(attachmentFile, 'rb')
        msg = MIMEBase(main_type, sub_type)
        msg.set_payload(fp.read())
        fp.close()
    filename = os.path.basename(attachmentFile)
    msg.add_header('Content-Disposition', 'attachment', filename=filename)
    message.attach(msg)

    return {'raw': base64.urlsafe_b64encode(message.as_string())}


def main():
    to = "to@address.com"
    sender = "from@address.com"
    subject = "subject"
    msgHtml = "Hi<br/>Html Email"
    msgPlain = "Hi\nPlain Email"
    SendMessage(sender, to, subject, msgHtml, msgPlain)
    # Send message with attachment: 
    SendMessage(sender, to, subject, msgHtml, msgPlain, '/path/to/file.pdf')

if __name__ == '__main__':
    main()

在没有浏览器的linux上运行此代码的提示：
如果您的linux环境没有浏览器来完成首次授权过程，则可以在笔记本电脑（mac或windows）上运行一次代码，然后将凭据复制到目标linux计算机。凭据通常存储在以下目标中：

~/.credentials/gmail-python-email-send.json

Answer 3

我将其修改为使用Python3，灵感来自Python Gmail API 'not JSON serializable'

import httplib2
import os
import oauth2client
from oauth2client import client, tools
import base64
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from apiclient import errors, discovery

SCOPES = 'https://www.googleapis.com/auth/gmail.send'
CLIENT_SECRET_FILE = 'client_secret.json'
APPLICATION_NAME = 'Gmail API Python Send Email'

def get_credentials():
    home_dir = os.path.expanduser('~')
    credential_dir = os.path.join(home_dir, '.credentials')
    if not os.path.exists(credential_dir):
        os.makedirs(credential_dir)
    credential_path = os.path.join(credential_dir, 'gmail-python-email-send.json')
    store = oauth2client.file.Storage(credential_path)
    credentials = store.get()
    if not credentials or credentials.invalid:
        flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
        flow.user_agent = APPLICATION_NAME
        credentials = tools.run_flow(flow, store)
        print('Storing credentials to ' + credential_path)
    return credentials

def SendMessage(sender, to, subject, msgHtml, msgPlain):
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    service = discovery.build('gmail', 'v1', http=http)
    message1 = CreateMessage(sender, to, subject, msgHtml, msgPlain)
    SendMessageInternal(service, "me", message1)

def SendMessageInternal(service, user_id, message):
    try:
        message = (service.users().messages().send(userId=user_id, body=message).execute())
        print('Message Id: %s' % message['id'])
        return message
    except errors.HttpError as error:
        print('An error occurred: %s' % error)

def CreateMessage(sender, to, subject, msgHtml, msgPlain):
    msg = MIMEMultipart('alternative')
    msg['Subject'] = subject
    msg['From'] = sender
    msg['To'] = to
    msg.attach(MIMEText(msgPlain, 'plain'))
    msg.attach(MIMEText(msgHtml, 'html'))
    raw = base64.urlsafe_b64encode(msg.as_bytes())
    raw = raw.decode()
    body = {'raw': raw}
    return body

def main():
    to = "to@address.com"
    sender = "from@address.com"
    subject = "subject"
    msgHtml = "Hi<br/>Html Email"
    msgPlain = "Hi\nPlain Email"
    SendMessage(sender, to, subject, msgHtml, msgPlain)

if __name__ == '__main__':
    main()