Python XML Feed 解析器找不到特定事件
Python XML Feed parser cant find specific event
我正在制作一个 python 脚本来读取 NWS CAP 警报，并寻找龙卷风警告。我的脚本足够阅读 XML，但是当发出龙卷风警告时，我无法将其设置为 return true。这是因为我的脚本只会读取 XML 中的事件之一。我现在已经让它读取了所有 XML，但是如果有龙卷风警告，它不会 return 为真，除非龙卷风警告是最后一个事件，因为它是如何循环的。任何人都可以在发出龙卷风警告时给我任何帮助，即使有其他警报，它也会 return 是吗？
import feedparser
import time
next_check = time.time()
tornado = False
while True:
if time.time() > next_check:
url = 'http://127.0.0.1/test.xml'
feed = feedparser.parse(url)
for entry in feed.entries:
if entry.has_key("cap_event") is False:
tornado = False
else:
if entry.cap_event == "Tornado Warning":
tornado = True
else:
tornado = False
print("Tornado: " + str(tornado))
print("EVENT: " + entry.cap_event)
next_check = time.time() + 5
这里有一个XML例子来测试它
<?xml version = '1.0' encoding = 'UTF-8' standalone = 'yes'?>
<!--
This atom/xml feed is an index to active advisories, watches and warnings
issued by the National Weather Service. This index file is not the complete
Common Alerting Protocol (CAP) alert message. To obtain the complete CAP
alert, please follow the links for each entry in this index. Also note the
CAP message uses a style sheet to convey the information in a human readable
format. Please view the source of the CAP message to see the complete data
set. Not all information in the CAP message is contained in this index of
active alerts.
-->
<feed
xmlns = 'http://www.w3.org/2005/Atom'
xmlns:cap = 'urn:oasis:names:tc:emergency:cap:1.1'
xmlns:ha = 'http://www.alerting.net/namespace/index_1.0'
>
<!-- TZN = <CDT> -->
<!-- TZO = <-5> -->
<!-- http-date = Mon, 04 May 2015 01:30:00 GMT -->
<id>https://alerts.weather.gov/cap/wwaatmget.php?x=NEC109&y=0</id>
<generator>NWS CAP Server</generator>
<updated>2015-05-03T20:30:00-05:00</updated>
<author>
<name>w-nws.webmaster@noaa.gov</name>
</author>
<title>Current Watches, Warnings and Advisories for Lancaster (NEC109) Nebraska Issued by the National Weather Service</title>
<link href='https://alerts.weather.gov/cap/wwaatmget.php?x=NEC109&y=0'/>
<entry>
<id>...</id>
<updated>2015-05-03T20:30:00-05:00</updated>
<published>2015-05-03T20:30:00-05:00</published>
<author>...</author>
<title>...</title>
<link href="http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23CC8.TornadoWarning.1253A7A25820NE.OAXTOROAX.267e2b2c2775d89536dfa15ab433866e"/>
<summary>...</summary>
<cap:event>Flood Warning</cap:event>
<cap:effective>2015-05-03T20:30:00-05:00</cap:effective>
<cap:expires>2015-05-03T21:00:00-05:00</cap:expires>
<cap:status>Actual</cap:status>
<cap:msgType>Alert</cap:msgType>
<cap:category>Met</cap:category>
<cap:urgency>Immediate</cap:urgency>
<cap:severity>Extreme</cap:severity>
<cap:certainty>Observed</cap:certainty>
<cap:areaDesc>Gage; Johnson; Lancaster</cap:areaDesc>
<cap:polygon>
40.52,-96.79 40.66,-96.64 40.57,-96.46 40.52,-96.46 40.52,-96.37 40.46,-96.25 40.26,-96.48 40.52,-96.79
</cap:polygon>
<cap:geocode>
<valueName>FIPS6</valueName>
<value>031067 031097 031109</value>
<valueName>UGC</valueName>
<value>NEC067 NEC097 NEC109</value>
</cap:geocode>
<cap:parameter>
<valueName>VTEC</valueName>
<value>/O.NEW.KOAX.TO.W.0002.150504T0130Z-150504T0200Z/</value>
</cap:parameter>
</entry>
<entry>
<id>http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23CC8.TornadoWarning.1253A7A25820NE.OAXTOROAX.267e2b2c2775d89536dfa15ab433866e</id>
<updated>2015-05-03T20:30:00-05:00</updated>
<published>2015-05-03T20:30:00-05:00</published>
<author>
<name>w-nws.webmaster@noaa.gov</name>
</author>
<title>Tornado Warning issued May 03 at 8:30PM CDT until May 03 at 9:00PM CDT by NWS</title>
<link href="http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23CC8.TornadoWarning.1253A7A25820NE.OAXTOROAX.267e2b2c2775d89536dfa15ab433866e"/>
<summary>THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * TORNADO WARNING FOR... NORTHWESTERN JOHNSON COUNTY IN SOUTHEASTERN NEBRASKA... NORTHEASTERN GAGE COUNTY IN SOUTHEASTERN NEBRASKA... SOUTHEASTERN LANCASTER COUNTY IN SOUTHEASTERN NEBRASKA... * UNTIL 900 PM CDT</summary>
<cap:event>Tornado Warning</cap:event>
<cap:effective>2015-05-03T20:30:00-05:00</cap:effective>
<cap:expires>2015-05-03T21:00:00-05:00</cap:expires>
<cap:status>Actual</cap:status>
<cap:msgType>Alert</cap:msgType>
<cap:category>Met</cap:category>
<cap:urgency>Immediate</cap:urgency>
<cap:severity>Extreme</cap:severity>
<cap:certainty>Observed</cap:certainty>
<cap:areaDesc>Gage; Johnson; Lancaster</cap:areaDesc>
<cap:polygon>40.52,-96.79 40.66,-96.64 40.57,-96.46 40.52,-96.46 40.52,-96.37 40.46,-96.25 40.26,-96.48 40.52,-96.79</cap:polygon>
<cap:geocode>
<valueName>FIPS6</valueName>
<value>031067 031097 031109</value>
<valueName>UGC</valueName>
<value>NEC067 NEC097 NEC109</value>
</cap:geocode>
<cap:parameter>
<valueName>VTEC</valueName>
<value>/O.NEW.KOAX.TO.W.0002.150504T0130Z-150504T0200Z/</value>
</cap:parameter>
</entry>
<entry>
<id>http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23430.SevereThunderstormWarning.1253A7A242A4NE.OAXSVROAX.d1cb461c9fb96a7e2ebbf6ddabdd25c7</id>
<updated>2015-05-03T20:08:00-05:00</updated>
<published>2015-05-03T20:08:00-05:00</published>
<author>
<name>w-nws.webmaster@noaa.gov</name>
</author>
<title>Severe Thunderstorm Warning issued May 03 at 8:08PM CDT until May 03 at 8:45PM CDT by NWS</title>
<link href="http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23430.SevereThunderstormWarning.1253A7A242A4NE.OAXSVROAX.d1cb461c9fb96a7e2ebbf6ddabdd25c7"/>
<summary>THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN LANCASTER COUNTY IN SOUTHEASTERN NEBRASKA... SOUTHWESTERN OTOE COUNTY IN SOUTHEASTERN NEBRASKA... * UNTIL 845 PM CDT * AT 808 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED OVER PANAMA...OR</summary>
<cap:event>Severe Thunderstorm Warning</cap:event>
<cap:effective>2015-05-03T20:08:00-05:00</cap:effective>
<cap:expires>2015-05-03T20:45:00-05:00</cap:expires>
<cap:status>Actual</cap:status>
<cap:msgType>Alert</cap:msgType>
<cap:category>Met</cap:category>
<cap:urgency>Immediate</cap:urgency>
<cap:severity>Severe</cap:severity>
<cap:certainty>Observed</cap:certainty>
<cap:areaDesc>Lancaster; Otoe</cap:areaDesc>
<cap:polygon>40.53,-96.6 40.67,-96.57 40.67,-96.32 40.52,-96.33 40.52,-96.56 40.53,-96.6</cap:polygon>
<cap:geocode>
<valueName>FIPS6</valueName>
<value>031109 031131</value>
<valueName>UGC</valueName>
<value>NEC109 NEC131</value>
</cap:geocode>
<cap:parameter>
<valueName>VTEC</valueName>
<value>/O.NEW.KOAX.SV.W.0045.150504T0108Z-150504T0145Z/</value>
</cap:parameter>
</entry>
</feed>
如果我理解你的问题是正确的，这应该是一个快速修复。
我对这个问题的理解是，您希望使用 feedparser 检查 xml 文件，看它是否包含以下 xml 条目：
<cap:event>Tornado Warning</cap:event>
如果它在文档中的任何地方发生，您希望将变量 tornado 存储为 True。
（你提到你想要 'return' true 但由于你不在函数中，我推测你的意思只是将变量更改为 True）
基本上你只需要删除语句的 else 部分。所以是这样的：
（我删除了 'if entry.has_key("cap_event") is False:'，因为我认为它也可能是多余的）
import feedparser
import time
next_check = time.time()
#tornado = False
while True:
if time.time() > next_check:
feed = feedparser.parse(r'/home/tomnl/test.xml')
# if tornado is declared here it means the file is checked a fresh
# each time
tornado = False
for entry in feed.entries:
if entry.cap_event == "Tornado Warning":
tornado = True
print("Tornado: " + str(tornado))
print("EVENT: " + entry.cap_event)
next_check = time.time() + 5
print("FINAL tornado", tornado)
希望对您有所帮助。
我正在制作一个 python 脚本来读取 NWS CAP 警报，并寻找龙卷风警告。我的脚本足够阅读 XML，但是当发出龙卷风警告时，我无法将其设置为 return true。这是因为我的脚本只会读取 XML 中的事件之一。我现在已经让它读取了所有 XML，但是如果有龙卷风警告，它不会 return 为真，除非龙卷风警告是最后一个事件，因为它是如何循环的。任何人都可以在发出龙卷风警告时给我任何帮助，即使有其他警报，它也会 return 是吗？
import feedparser
import time
next_check = time.time()
tornado = False
while True:
if time.time() > next_check:
url = 'http://127.0.0.1/test.xml'
feed = feedparser.parse(url)
for entry in feed.entries:
if entry.has_key("cap_event") is False:
tornado = False
else:
if entry.cap_event == "Tornado Warning":
tornado = True
else:
tornado = False
print("Tornado: " + str(tornado))
print("EVENT: " + entry.cap_event)
next_check = time.time() + 5
这里有一个XML例子来测试它
<?xml version = '1.0' encoding = 'UTF-8' standalone = 'yes'?>
<!--
This atom/xml feed is an index to active advisories, watches and warnings
issued by the National Weather Service. This index file is not the complete
Common Alerting Protocol (CAP) alert message. To obtain the complete CAP
alert, please follow the links for each entry in this index. Also note the
CAP message uses a style sheet to convey the information in a human readable
format. Please view the source of the CAP message to see the complete data
set. Not all information in the CAP message is contained in this index of
active alerts.
-->
<feed
xmlns = 'http://www.w3.org/2005/Atom'
xmlns:cap = 'urn:oasis:names:tc:emergency:cap:1.1'
xmlns:ha = 'http://www.alerting.net/namespace/index_1.0'
>
<!-- TZN = <CDT> -->
<!-- TZO = <-5> -->
<!-- http-date = Mon, 04 May 2015 01:30:00 GMT -->
<id>https://alerts.weather.gov/cap/wwaatmget.php?x=NEC109&y=0</id>
<generator>NWS CAP Server</generator>
<updated>2015-05-03T20:30:00-05:00</updated>
<author>
<name>w-nws.webmaster@noaa.gov</name>
</author>
<title>Current Watches, Warnings and Advisories for Lancaster (NEC109) Nebraska Issued by the National Weather Service</title>
<link href='https://alerts.weather.gov/cap/wwaatmget.php?x=NEC109&y=0'/>
<entry>
<id>...</id>
<updated>2015-05-03T20:30:00-05:00</updated>
<published>2015-05-03T20:30:00-05:00</published>
<author>...</author>
<title>...</title>
<link href="http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23CC8.TornadoWarning.1253A7A25820NE.OAXTOROAX.267e2b2c2775d89536dfa15ab433866e"/>
<summary>...</summary>
<cap:event>Flood Warning</cap:event>
<cap:effective>2015-05-03T20:30:00-05:00</cap:effective>
<cap:expires>2015-05-03T21:00:00-05:00</cap:expires>
<cap:status>Actual</cap:status>
<cap:msgType>Alert</cap:msgType>
<cap:category>Met</cap:category>
<cap:urgency>Immediate</cap:urgency>
<cap:severity>Extreme</cap:severity>
<cap:certainty>Observed</cap:certainty>
<cap:areaDesc>Gage; Johnson; Lancaster</cap:areaDesc>
<cap:polygon>
40.52,-96.79 40.66,-96.64 40.57,-96.46 40.52,-96.46 40.52,-96.37 40.46,-96.25 40.26,-96.48 40.52,-96.79
</cap:polygon>
<cap:geocode>
<valueName>FIPS6</valueName>
<value>031067 031097 031109</value>
<valueName>UGC</valueName>
<value>NEC067 NEC097 NEC109</value>
</cap:geocode>
<cap:parameter>
<valueName>VTEC</valueName>
<value>/O.NEW.KOAX.TO.W.0002.150504T0130Z-150504T0200Z/</value>
</cap:parameter>
</entry>
<entry>
<id>http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23CC8.TornadoWarning.1253A7A25820NE.OAXTOROAX.267e2b2c2775d89536dfa15ab433866e</id>
<updated>2015-05-03T20:30:00-05:00</updated>
<published>2015-05-03T20:30:00-05:00</published>
<author>
<name>w-nws.webmaster@noaa.gov</name>
</author>
<title>Tornado Warning issued May 03 at 8:30PM CDT until May 03 at 9:00PM CDT by NWS</title>
<link href="http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23CC8.TornadoWarning.1253A7A25820NE.OAXTOROAX.267e2b2c2775d89536dfa15ab433866e"/>
<summary>THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * TORNADO WARNING FOR... NORTHWESTERN JOHNSON COUNTY IN SOUTHEASTERN NEBRASKA... NORTHEASTERN GAGE COUNTY IN SOUTHEASTERN NEBRASKA... SOUTHEASTERN LANCASTER COUNTY IN SOUTHEASTERN NEBRASKA... * UNTIL 900 PM CDT</summary>
<cap:event>Tornado Warning</cap:event>
<cap:effective>2015-05-03T20:30:00-05:00</cap:effective>
<cap:expires>2015-05-03T21:00:00-05:00</cap:expires>
<cap:status>Actual</cap:status>
<cap:msgType>Alert</cap:msgType>
<cap:category>Met</cap:category>
<cap:urgency>Immediate</cap:urgency>
<cap:severity>Extreme</cap:severity>
<cap:certainty>Observed</cap:certainty>
<cap:areaDesc>Gage; Johnson; Lancaster</cap:areaDesc>
<cap:polygon>40.52,-96.79 40.66,-96.64 40.57,-96.46 40.52,-96.46 40.52,-96.37 40.46,-96.25 40.26,-96.48 40.52,-96.79</cap:polygon>
<cap:geocode>
<valueName>FIPS6</valueName>
<value>031067 031097 031109</value>
<valueName>UGC</valueName>
<value>NEC067 NEC097 NEC109</value>
</cap:geocode>
<cap:parameter>
<valueName>VTEC</valueName>
<value>/O.NEW.KOAX.TO.W.0002.150504T0130Z-150504T0200Z/</value>
</cap:parameter>
</entry>
<entry>
<id>http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23430.SevereThunderstormWarning.1253A7A242A4NE.OAXSVROAX.d1cb461c9fb96a7e2ebbf6ddabdd25c7</id>
<updated>2015-05-03T20:08:00-05:00</updated>
<published>2015-05-03T20:08:00-05:00</published>
<author>
<name>w-nws.webmaster@noaa.gov</name>
</author>
<title>Severe Thunderstorm Warning issued May 03 at 8:08PM CDT until May 03 at 8:45PM CDT by NWS</title>
<link href="http://alerts.weather.gov/cap/wwacapget.php?x=NE1253A7A23430.SevereThunderstormWarning.1253A7A242A4NE.OAXSVROAX.d1cb461c9fb96a7e2ebbf6ddabdd25c7"/>
<summary>THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN LANCASTER COUNTY IN SOUTHEASTERN NEBRASKA... SOUTHWESTERN OTOE COUNTY IN SOUTHEASTERN NEBRASKA... * UNTIL 845 PM CDT * AT 808 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED OVER PANAMA...OR</summary>
<cap:event>Severe Thunderstorm Warning</cap:event>
<cap:effective>2015-05-03T20:08:00-05:00</cap:effective>
<cap:expires>2015-05-03T20:45:00-05:00</cap:expires>
<cap:status>Actual</cap:status>
<cap:msgType>Alert</cap:msgType>
<cap:category>Met</cap:category>
<cap:urgency>Immediate</cap:urgency>
<cap:severity>Severe</cap:severity>
<cap:certainty>Observed</cap:certainty>
<cap:areaDesc>Lancaster; Otoe</cap:areaDesc>
<cap:polygon>40.53,-96.6 40.67,-96.57 40.67,-96.32 40.52,-96.33 40.52,-96.56 40.53,-96.6</cap:polygon>
<cap:geocode>
<valueName>FIPS6</valueName>
<value>031109 031131</value>
<valueName>UGC</valueName>
<value>NEC109 NEC131</value>
</cap:geocode>
<cap:parameter>
<valueName>VTEC</valueName>
<value>/O.NEW.KOAX.SV.W.0045.150504T0108Z-150504T0145Z/</value>
</cap:parameter>
</entry>
</feed>
如果我理解你的问题是正确的，这应该是一个快速修复。
我对这个问题的理解是，您希望使用 feedparser 检查 xml 文件，看它是否包含以下 xml 条目：
<cap:event>Tornado Warning</cap:event>
如果它在文档中的任何地方发生，您希望将变量 tornado 存储为 True。
（你提到你想要 'return' true 但由于你不在函数中，我推测你的意思只是将变量更改为 True）
基本上你只需要删除语句的 else 部分。所以是这样的：
（我删除了 'if entry.has_key("cap_event") is False:'，因为我认为它也可能是多余的）
import feedparser
import time
next_check = time.time()
#tornado = False
while True:
if time.time() > next_check:
feed = feedparser.parse(r'/home/tomnl/test.xml')
# if tornado is declared here it means the file is checked a fresh
# each time
tornado = False
for entry in feed.entries:
if entry.cap_event == "Tornado Warning":
tornado = True
print("Tornado: " + str(tornado))
print("EVENT: " + entry.cap_event)
next_check = time.time() + 5
print("FINAL tornado", tornado)
希望对您有所帮助。