python - 如何使用 python 列表理解/字典将每一列打印为唯一变量

Question

假设我们有一个 csv

PROPERTY_ID,CLIENT_ID,FROM_YEAR
1,5,2015
2,6,2015
3,9,2015
4,9,2015

我试图将 CLIENT_ID、PROPERTY_ID、FROM_YEAR 的每个唯一组合传递到字典或列表中，因此我可以将每个“PROPERTY_ID、CLIENT_ID、FROM_YEAR”对放入 MySQL 查询中:

SELECT * FROM client_5 WHERE PROPERTY_ID = 1 and FROM_YEAR = 2015;

SELECT * FROM client_6 WHERE PROPERTY_ID = 2 and FROM_YEAR = 2015;

SELECT * FROM client_9 WHERE PROPERTY_ID = 3 and FROM_YEAR = 2015;

SELECT * FROM client_9 WHERE PROPERTY_ID = 4 and FROM_YEAR = 2015;

从变量的角度:

1st round:
$CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=5,1,2015

2nd round
$CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=6,2,2015

3rd round
$CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=9,3,2015

4th round
$CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=9,4,2015

我尝试使用列表理解:

df = pd.read_csv("test.csv")

df2=df.apply(tuple, 1).unique().tolist()

for CLIENT_ID in [x[0] for x in df2]:

    CLIENT_ID=CLIENT_ID.astype('str')

    print "SELECT * FROM client"+CLIENT_ID

    for PROPERTY_CODE in [y[1] for y in df2]:

        PROPERTY_CODE=PROPERTY_CODE.astype('str')

        print "WHERE PROPERTY_ID = "+PROPERTY_CODE

它返回以下内容，这不是我们要找的:

SELECT * FROM client_5
WHERE FK_PROPERTY_ID = 1
WHERE FK_PROPERTY_ID = 2
WHERE FK_PROPERTY_ID = 3
WHERE FK_PROPERTY_ID = 4

谁能指教一下？谢谢。

Answer 1

我会使用格式

fstr = '$CLIENT_ID,$PROPERTY_ID,$FROM_YEAR={CLIENT_ID},{PROPERTY_ID},{FROM_YEAR}'
df.drop_duplicates().apply(lambda x: fstr.format(**x), 1)

0    $CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=5,1,2015
1    $CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=6,2,2015
2    $CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=9,3,2015
3    $CLIENT_ID,$PROPERTY_ID,$FROM_YEAR=9,4,2015
dtype: object