Question

import serial
import MySQLdb

dbConn = MySQLdb.connect("localhost","root","test","ISEF_DB") or die ("Could not connect to database")
cursor = dbConn.cursor()

device = '/dev/ttyACM0'

try:
    print "Trying...",device
    arduino = serial.Serial(device, 250000)
except:
    print "Failed to connect on",device

try:
    data = arduino.readline() #read data
#   pieces = data.split("\t")
    print "The data is:",data
    if data == 461518B1:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '461518B1'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 46154D41:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '46154D41'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 4615A161:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '4615A161'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 4616A511:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '4616A511'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 46193031:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '46193031'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 46196771:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '46196771'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 461A79D1:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '461A79D1'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 46211881:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '46211881'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 465598F1:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '465598F1'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    elif data == 9A2DCDE4:
        try:
            cursor.execute("UPDATE `ISEF_DB`.`attendance` SET `present`='1' WHERE `id` = '9A2DCDE4'")
            dbConn.commit()
            cursor.close()
            print "data inserted"
        except MySQLdb.IntegrityError:
            print "Failed to insert data"
        finally:
            cursor.close()
            print "done"
    else:
        print "Card not recognized"

except:
    print "Failed to get data"

此代码给出了以下错误

  File "test.py", line 19
    if 461518B1 == data:
              ^
SyntaxError: invalid syntax

我要做的是将变量与字符串进行比较，但它不起作用。我看不出我做错了什么。数据值只能是包含数字和字母的10个if语句之一。我没有看到任何语法问题。有人可以帮忙解决这个错误吗？

谢谢

Answer 1

虽然这并没有直接回答你的问题（在评论中已经充分解决了这个问题， viz ，

"461518B1"不是字符串，'461518B1'或id_values = ['461518B1', '46154D41', '4615A161', '4616A511', '46193031', '46196771', '461A79D1', '46211881', '465598F1', '9A2DCDE4'] data = arduino.readline() # read data data = data.strip() # get rid of whitespace like '\r\n' print "The data is:",data if data in id_values: try: cursor.execute("UPDATE 'ISEF_DB'.'attendance' SET 'present'='1' WHERE 'id' = '" + data + "'") dbConn.commit() cursor.close() print "data inserted" except MySQLdb.IntegrityError: print "Failed to insert data" finally: cursor.close() print "done" else: print "Card not recognized {}".format(data)

（使用引号指定字符串文字）

我想指出您可以修改代码以避免冗余，因为您似乎在每个if / elif`块中使用相同的代码块：

a = sin((1−f)⋅δ) / sin δ
b = sin(f⋅δ) / sin δ
x = a ⋅ cos φ1 ⋅ cos λ1 + b ⋅ cos φ2 ⋅ cos λ2
y = a ⋅ cos φ1 ⋅ sin λ1 + b ⋅ cos φ2 ⋅ sin λ2
z = a ⋅ sin φ1 + b ⋅ sin φ2
φi = atan2(z, √x² + y²)
λi = atan2(y, x)

Python 2.7.3如果将变量与字符串进行比较

1 个答案: