Question

我收到以下错误：

File "pymon.py", line 18
sql += "'" + str(gpu['GPU Clock'] + "', "
  ^

如果有帮助，这是代码的一部分：

def parsedata(data, ngpu):

for gpu in data:

    sql = "UPDATE pythondb SET (minerid, temp, load, hashrate, accepted, rejected, coreclock, memclock, power, hwerror) VALUES "
    sql += "("
    sql += "'" + str(gpu['Temperature']) + "', "
    sql += "'" + str(gpu['GPU Activity']) + "', "
    sql += "'" + str(gpu['MHS av'] * 1000) + "', "
    sql += "'" + str(gpu['Accepted']) + "', "
    sql += "'" + str(gpu['Rejected'] + "', "
    sql += "'" + str(gpu['GPU Clock'] + "', "
    sql += "'" + str(gpu['Memory Clock'] + "', "
    sql += "'" + str(gpu['GPU Voltage'] + "', "
    sql += "'" + str(gpu['Device Hardware']) + "'"
    sql += ") WHERE id='%d'", ngpu
    sql += ";"

return sqlstatement

我打赌这是非常愚蠢的事情，但我无法找到它是什么。

Answer 1

您在前一行缺少右括号：

sql += "'" + str(gpu['Memory Clock'] + "', "
#           ----^      but not here ^

多行中缺少str()函数的右括号。

你真的不应该使用字符串插值来构建SQL查询;您将使用SQL 参数。这是如何工作的取决于您的数据库适配器。

例如，在sqite3中，您使用?作为占位符; MySQLdb使用%s代替。一个sqlite的例子是：

sql = """\
    UPDATE pythondb SET (
        minerid, temp, load, hashrate, accepted, rejected,
        coreclock, memclock, power, hwerror)
    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
    WHERE id=?"
"""
cursor.execute(sql, (
    gpu['Temperature'], gpu['GPU Activity'], gpu['MHS av'] * 1000,
    gpu['Accepted'], gpu['Rejected'], gpu['GPU Clock'], gpu['Memory Clock'],
    gpu['GPU Voltage'], gpu['Device Hardware'])
)

即使您不能使用SQL参数，您也应该了解Python String Formatting;你可以拥有：

sql = """\
    UPDATE pythondb SET (
        minerid, temp, load, hashrate, accepted, rejected,
        coreclock, memclock, power, hwerror)
    VALUES (
        '{0[Temperature]}', '{0[GPU Activity]}',
        '{1}', '{0[Accepted]}', '{0[Rejected]}', '{0[GPU Clock]}',
        '{0[Memory Clock]}', '{0[GPU Voltage]}', '{0[Device Hardware]}')
   WHERE id='{2}';
""".format(gpu, gpu['MHS av'] * 1000, ngpu)

除了将SQL值插入到这样的SQL语句中仍然是一个非常糟糕的想法。

Python语法错误无缘无故？

1 个答案: