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期望的结果：我正在尝试生成我们救护车位置的可缩放矢量图形和指示救护车是否繁忙、停止服务、在宿舍等的颜色。我们在路上的护理人员可以将其视为网页和将我们所有救护车的配置视为地图。一目了然，他们可以看到哪些救护车很忙，哪些是空闲的。

我的方法：我正在使用带有 pyodbc 和 xml.etree 的 python 2.7。我正在查询我们的数据库以确定最近的救护车状态，循环遍历数组并生成数据的 svg。

问题：当输出写入文本并使用记事本打开 .svg 文件时，我看到有一长行输出。我希望它是嵌套输出。如果您查看下面的代码，您会发现我只测试了两辆救护车。但是我的系统中有五十辆救护车。我不能有数千个字符的一长行。

问题：如何让 python / ElementTree 在输出中写出换行符？

代码如下图：

import pyodbc
from xml.etree import ElementTree as et

cnxn = pyodbc.connect('DRIVER={SQL Server}; SERVER=my server; DATABASE=my database; UID=my user id; PWD=my password')
cursor = cnxn.cursor()
AmbulanceStatus = """
WITH Maxtimes AS
(
SELECT
  MAX(M_Manpower_PK) AS [FirstRecord]
, PUN_UnitID
FROM MManpower
INNER JOIN PUnit ON M_kUnit = PUN_Unit_PK
WHERE PUN_UnitID LIKE 'M__'
OR PUN_UnitID LIKE 'FBA__'
AND M_tTime > DATEADD(HOUR, -24, GETDATE())
GROUP BY PUN_UnitID
)
,
MaxAttributes AS
(
SELECT
  M_Manpower_PK
, M_tTime
, M_Code
, CASE 
  WHEN M_Code IN ('USTA', 'USER', 'USOL', 'USAR', 'USIZ', 'UF', 'USTR', 'USDP') THEN 'Working'
  WHEN M_Code IN ('USAQ', 'USRQ') THEN 'Free'
  WHEN M_Code IN ('USES', 'USSB', 'USAS', 'USRS', 'USLC') THEN 'Standby'
  WHEN M_Code IN ('USOS') THEN 'OutofService'
  ELSE 'NA'
  END AS [Disposition]
FROM MManpower
INNER JOIN PUnit ON M_kUnit = PUN_Unit_PK
WHERE PUN_UnitID LIKE 'M__'
OR PUN_UnitID LIKE 'FBA__'
AND M_tTime > DATEADD(HOUR, -24, GETDATE())
)

SELECT
  MaxTimes.firstRecord AS [RecordNumber]
, MaxTimes.PUN_UnitID AS [Ambulance]
, CONVERT(VARCHAR(20), MaxAttributes.M_tTime, 108) AS [FinalTimeStamp]
, MaxAttributes.M_Code AS [UnitStatus]
, MaxAttributes.Disposition AS [Disposition]
FROM Maxtimes
LEFT OUTER JOIN MaxAttributes ON Maxtimes.FirstRecord=MaxAttributes.M_Manpower_PK
"""

cursor.execute(AmbulanceStatus)

Ambulances = cursor.fetchall()

cursor.close()

for ambulance in Ambulances:
    print ambulance

doc = et.Element('svg', width='792', height='612', version='1.1', xmlns='http://www.w3.org/2000/svg')
#===============================================================================
# I have no idea how to implement the following 15 lines of code. I downloaded them from the internet. I have googled this question and someone believes the following lines of code can help write out carriage returns.
#===============================================================================
# def indent(elem, level=0):
#    i = "\n" + level * "  "
#    if len(elem):
#        if not elem.text or not elem.text.strip():
#            elem.text = i + "  "
#        if not elem.tail or not elem.tail.strip():
#            elem.tail = i
#        for elem in elem:
#            indent(elem, level + 1)
#        if not elem.tail or not elem.tail.strip():
#            elem.tail = i
#    else:
#        if level and (not elem.tail or not elem.tail.strip()):
#            elem.tail = i
#===============================================================================
j = 0
#===============================================================================
# medic 19
#===============================================================================
while j < len(Ambulances):
    if Ambulances[j][1] == 'M19' and Ambulances[j][4] == 'Free':
        fillColor = 'aliceblue'
        fillText = 'black'
        et.SubElement(doc, 'circle', cx='520', cy='85', r='10', stroke='black', fill=fillColor)
        text = et.Element('text', x='520', y='85', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M19' and Ambulances[j][4] == 'Working':
        fillColor = 'red'
        fillText = 'white'
        et.SubElement(doc, 'circle', cx='520', cy='85', r='10', fill=fillColor)
        text = et.Element('text', x='520', y='85', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M19' and Ambulances[j][4] == 'Standby':
        fillColor = 'green'
        fillText = 'white'
        et.SubElement(doc, 'circle', cx='520', cy='85', r='10', fill=fillColor)
        text = et.Element('text', x='520', y='85', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M19' and Ambulances[j][4] == 'OutofService':
        fillColor = 'black'
        fillText = 'white'
        et.SubElement(doc, 'circle', cx='520', cy='85', r='10', fill=fillColor)
        text = et.Element('text', x='520', y='85', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M19' and Ambulances[j][4] == 'NA':
        fillColor = 'pink'
        fillText = 'blue'
        et.SubElement(doc, 'circle', cx='520', cy='85', r='10', fill=fillColor)
        text = et.Element('text', x='520', y='85', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)
#===============================================================================
# medic 16
#===============================================================================
    elif Ambulances[j][1] == 'M16' and Ambulances[j][4] == 'Free':
        fillColor = 'aliceblue'
        fillText = 'black'
        et.SubElement(doc, 'circle', cx='28.80024', cy='45.8372', r='10', stroke='black', fill=fillColor)
        text = et.Element('text', x='28.80024', y='45.8372', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M16' and Ambulances[j][4] == 'Working':
        fillColor = 'red'
        fillText = 'blue'
        et.SubElement(doc, 'circle', cx='28.80024', cy='45.8372', r='10', fill=fillColor)
        text = et.Element('text', x='28.80024', y='45.8372', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M16' and Ambulances[j][4] == 'Standby':
        fillColor = 'green'
        fillText = 'white'
        et.SubElement(doc, 'circle', cx='28.80024', cy='45.8372', r='10', fill=fillColor)
        text = et.Element('text', x='28.80024', y='45.8372', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M16' and Ambulances[j][4] == 'OutofService':
        fillColor = 'black'
        fillText = 'white'
        et.SubElement(doc, 'circle', cx='28.80024', cy='45.8372', r='10', fill=fillColor)
        text = et.Element('text', x='28.80024', y='45.8372', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

    elif Ambulances[j][1] == 'M16' and Ambulances[j][4] == 'NA':
        fillColor = 'pink'
        fillText = 'blue'
        et.SubElement(doc, 'circle', cx='28.80024', cy='45.8372', r='10', fill=fillColor)
        text = et.Element('text', x='28.80024', y='45.8372', fill=fillText, style='font-family:Sans;font-size:12px;text-anchor:middle;dominant-baseline:top')
        text.text = Ambulances[j][1]
        doc.append(text)

#===============================================================================
# loop through the array
#===============================================================================
    j = j + 1

# ElementTree 1.2 doesn't write the SVG file header errata, so do that manually
f = open('C:\sample.svg', 'w')
f.write('<?xml version=\'1.0\' standalone=\'no\'?>\n')
f.write('<!DOCTYPE svg PUBLIC \'-//W3C//DTD SVG 1.1//EN\'\n')
f.write('\'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\'>\n')
f.write(et.tostring(doc))
f.close()
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1 回答 1

2

查看此链接；

http://broadcast.oreilly.com/2010/03/pymotw-creating-xml-documents.html

from xml.dom import minidom

def prettify(elem):
    """Return a pretty-printed XML string for the Element.
    """
    rough_string = ET.tostring(elem, 'utf-8')
    reparsed = minidom.parseString(rough_string)
    return reparsed.toprettyxml(indent="  ")
于 2013-04-08T11:32:47.083 回答