Question

该程序绘制从MySQL中的数据库获得的传感器的值的图形。我试图仅在来自数据库的值大于25时向我发送电子邮件，但会向我发送错误消息：

TypeError：“ str”和“ int”的实例之间不支持“>”

我的问题是如何创建条件，以便它使用来自数据库的值（“值”）发送邮件。

这是代码：

def update_graph(dark_theme):
    dataSQL = []
    X = deque(maxlen=10)    
    Y = deque(maxlen=10)

    sql_conn = MySQLdb.connect('localhost', 'root', 'root', 'DB')
    cursor = sql_conn.cursor()
    cursor.execute("SELECT value, timestamp FROM sensorParser where sensor='TC'")
    rows = cursor.fetchall()
    for row in rows:
        dataSQL.append(list(row))
        labels = ['value','timestamp']
        df = pd.DataFrame.from_records(dataSQL, columns=labels)
        X = df['timestamp']
        Y = df['value']

    data = plotly.graph_objs.Scatter(
        x=list(X),
        y=list(Y),
        name='TEMP',
        mode='lines+markers'
    )

    if (df['value'] > 25):
        email = 'email@gmail.com'
        password = 'pass'
        send_to_email = 'email2@gmail.com'
        subject = 'ALERT'
        message = 'Alert'
        file_location = 'C:\\Users\\User\\Desktop\\prograpython\\p.jpg'

        msg = MIMEMultipart()
        msg['From'] = email
        msg['To'] = send_to_email
        msg['Subject'] = subject

        msg.attach(MIMEText(message, 'plain'))

        filename = os.path.basename(file_location)
        attachment = open(file_location, "rb")
        part = MIMEBase('application', 'octet-stream')
        part.set_payload((attachment).read())
        encoders.encode_base64(part)
        part.add_header('Content-Disposition',
                        "attachment;filename= %s" % filename)

        msg.attach(part)

        server = smtplib.SMTP('smtp.gmail.com', 587)
        server.starttls()
        server.login(email, password)
        text = msg.as_string()
        server.sendmail(email, send_to_email, text)
        server.quit()

    return {
        'data': [data],
        'layout' : go.Layout(title="TEMPERATURA",
                             xaxis={'title':'HORA/FECHA'},
                             yaxis={'title':'°C'})
    }

致谢。

Answer 1

使用从字符串到浮点的转换： if (float(df['value']) > 25):

Answer 2

要修复您的错误，您需要将数据库中的字符串转换为整数。试试：

if (int(df['value']) > 25):

Answer 3

将温度值转换为浮动值：

Y = df['value'].astype(float)

字符串与整数的比较

3 个答案: