问题描述
这是从我的查询中获取数据并将其打包为csv文件的python代码。
...
col_headers = [ i[0] for i in cursor.description ]
rows = [ list(i) for i in cursor.fetchall()]
df = pd.DataFrame(rows,columns=col_headers)
df.to_csv("PremiseCPE.csv",index=False)
for row in cursor.fetchall():
print (row)
...
传入数据在列中。我需要添加一个名为“地标”的附加列(#6)。 然后,我需要根据列#3中称为cpestatus的值,在数据库的每个输出的新列行中添加值。以下是我在创建kml文件时尝试过的查询结构类型:
...
iif (row[4]) = 'Off',(row[6]) = "http://maps.google.com/mapfiles/kml/shapes/forbidden.png"
ElseIf (row[4]) = 'Active',(row[6]) = "http://maps.google.com/mapfiles/kml/shapes/ranger_station.png"
ElseIf (row[4]) = 'Ready,(row[6]) = "http://maps.google.com/mapfiles/kml/shapes/mechanic.png"
ElseIf (row[4]) = 'Alarm',(row[6]) = "http://maps.google.com/mapfiles/kml/shapes/caution.png"
ElseIf (row[4]) = 'Null',(row[6]) = "http://maps.google.com/mapfiles/kml/shapes/white_bubble.png"
End If
...
目标是尝试在csv文件级别运行此程序。
有人可以帮忙吗?
解决方法
正如@MattDMo所说,您需要在数据帧中执行此操作,然后再编写CSV。另外,相对于Python中的长if...elif...else
,我更喜欢字典查找。最后,我建议使用pd.read_sql查询数据库并创建df。
import pandas as pd
col_headers = ['col1','cols2','yada','cpeStatus','murgatroyd','noimagination']
rows = [[1,2,3,'Off','is',42],[2,4,42,'Active','the',[3,9,12,'Ready','best',[4,16,20,'name',[5,25,30,'Alarm','no',[6,36,'Null','its',[7,49,56,'Danger','not',]
df = pd.DataFrame(rows,columns=col_headers)
plmks = {'Off': "forbidden.png",'Active': "ranger_station.png",'Ready': "mechanic.png",'Alarm': "caution.png",'Null': "white_bubble.png"}
df['Placemarks'] = [plmks.get(st,"headslap.png") for st in df['cpeStatus']]
print(df)
df.to_csv("PremiseCPE.csv",index=False)
产生以下df:
0 1 2 3 Off is 42 forbidden.png
1 2 4 42 Active the 42 ranger_station.png
2 3 9 12 Ready best 42 mechanic.png
3 4 16 20 Off name 42 forbidden.png
4 5 25 30 Alarm no 42 caution.png
5 6 36 42 Null its 42 white_bubble.png
6 7 49 56 Danger not 42 headslap.png
和以下CSV:
col1,cols2,yada,cpeStatus,murgatroyd,noimagination,Placemarks
1,Off,is,forbidden.png
2,Active,the,ranger_station.png
3,Ready,best,mechanic.png
4,name,forbidden.png
5,Alarm,no,caution.png
6,Null,its,white_bubble.png
7,Danger,not,headslap.png