is对比内存的，python把不可变对象都指向同一内存





==对比数值的


![在这里插入图片描述](/static/img/images/00493.png)

Python中is和==的区别

Python





```handlebars
# -*- coding: utf-8 -*-
import smtplib
from email.mime.text import MIMEText
from email.header import Header
def send_email_to_d(mesg, receivers=['dyl.sun@chinaentropy.com', 'kes.xie@chinaentropy.com']):
    # 第三方 SMTP 服务
    mail_host = "smtp.exmail.qq.com"  # 设置服务器
    mail_user = "kes.xie@chinaentropy.com"  # 用户名
    mail_pass = "43123131"  # 口令 密码
    sender = 'kes.xie@chinaentropy.com'
    message = MIMEText(mesg, 'plain', 'utf-8')
    message['From'] = Header("kes", 'utf-8')
    message['To'] = Header("dyl", 'utf-8')
    subject = '数据库报错'
    message['Subject'] = Header(subject, 'utf-8')
    try:
        smtpObj = smtplib.SMTP_SSL(mail_host, 465)
        smtpObj.login(mail_user, mail_pass)
        smtpObj.sendmail(sender, receivers, message.as_string())
        smtpObj.quit()
        print("邮件发送成功")
    except smtplib.SMTPException:
        print("Error: 无法发送邮件")
```

ptyhon 企业邮箱 发邮件

Python





```handlebars
np.isnan(arr).sum()
```

python 统计array中nan的个数要怎么做

pColor网格和着色





[https://www.osgeo.cn/matplotlib/gallery/images_contours_and_fields/pcolormesh_grids.html](https://www.osgeo.cn/matplotlib/gallery/images_contours_and_fields/pcolormesh_grids.html)

![在这里插入图片描述](/static/img/images/00506.png)

python matplotlib pColor 网格线 消除

time_data就是一个numpy.datetime64




```handlebars
import pandas as pd
datatime = str(pd.to_datetime(time_data))
```