无法关闭 csv 来将其删除

Question

我有一项日常任务非常适合自动化，因此我决定将其用作学习 Python 的项目。我需要做的是将一些 .xlsx 文件转换为 .csv，然后将每个文件通过电子邮件发送到特定的电子邮件地址。下面是我所得到的，直到接近结束时它都工作得很好。我希望它在发送后删除 csv 副本。File1.csv 被删除，但 file2.csv 没有被删除，因为它仍在另一个进程中打开。PermissionError: [WinError 32] 该进程无法访问该文件，因为该文件正在被另一个进程使用：“C:\Drop\file2.csv”所以很明显 csv 需要关闭，但我无法弄清楚哪个进程打开了它以及如何关闭它。import osfrom datetime import datetimeimport pandas as pdimport smtplibfrom email.mime.text import MIMETextfrom email.mime.multipart import MIMEMultipartfrom email.mime.base import MIMEBasefrom email import encodersfiles = []drop_path = 'C:\\Data Drop\\'path = os.chdir(drop_path)datestamp =  datetime.now().strftime(' (%m-%d-%Y)')#Make a CSV copy of each filefor c in os.listdir(path):    file_name, file_ext = os.path.splitext(c)    xlsx = pd.read_excel(file_name+file_ext)    xlsx.to_csv(file_name+'.csv', encoding='utf-8')    files.append(file_name+'.csv')print('CSV copies created\n')#Send to appropriate email addressesrecipient = ''for s in files:    print('Sending ',s)    if s == 'file1.csv':        recipient = '<[e-mail]>'    elif s == 'file2.csv':        recipient = '<[e-mail]>'    email_user = '[e-mail]'    email_password = 'password'    email_send = recipient    msg = MIMEMultipart()    msg['From'] = email_user    msg['To'] = email_send    msg['Subject'] = "Data transmittal"    body = 'Data transmittal attached'    msg.attach(MIMEText(body,'plain'))    attached_file = s    attachment  = open(attached_file,'rb')    part = MIMEBase('application','octet-stream')    part.set_payload((attachment).read())    encoders.encode_base64(part)    part.add_header('Content-Disposition',"attachment; filename= "+attached_file)    msg.attach(part)    text = msg.as_string()    server = smtplib.SMTP('smtp.gmail.com',587)    server.starttls()    server.login(email_user,email_password)    server.sendmail(email_user,email_send,text)    print(s,'sent.\n')    server.quit()

Answer 1

您的错误是打开attachment但从未关闭它。

代替 ：attachment  = open(attached_file,'rb')

使用with open()上下文管理器：

with open(attached_file,'rb') as attachment:

    part = MIMEBase('application','octet-stream')

    part.set_payload((attachment).read())

# here attachment is closed automatically

encoders.encode_base64(part)

part.add_header('Content-Disposition',"attachment; filename= "+attached_file)