如何实现python在xml标签之间查找值？

Question

我正在使用谷歌网站检索天气信息,我想在XML标签之间找到值.下面的代码给我一个城市的天气状况,但我无法获得其他参数,如温度,如果可能的话,解释代码中隐含的分离函数的工作:

import urllib

def getWeather(city):

    #create google weather api url
    url = "http://www.google.com/ig/api?weather=" + urllib.quote(city)

    try:
        # open google weather api url
        f = urllib.urlopen(url)
    except:
        # if there was an error opening the url, return
        return "Error opening url"

    # read contents to a string
    s = f.read()

    # extract weather condition data from xml string
    weather = s.split("<current_conditions><condition data=\"")[-1].split("\"")[0]

    # if there was an error getting the condition, the city is invalid


    if weather == "<?xml version=":
        return "Invalid city"

    #return the weather condition
    return weather

def main():
    while True:
        city = raw_input("Give me a city: ")
        weather = getWeather(city)
        print(weather)

if __name__ == "__main__":
    main()

谢谢

Answer 1

使用

一个

PARSER

您无法使用正则表达式解析XML,因此请勿尝试.这是在Python中找到XML解析器的开始.这是一个学习在Python中解析XML的好网站.

更新:鉴于有关PyS60的新信息,这里是使用诺基亚网站XML的文档.

更新2:@Nas Banov请求了示例代码,所以这里是:

import urllib

from xml.parsers import expat

def start_element_handler(name, attrs):
    """
    My handler for the event that fires when the parser sees an
    opening tag in the XML.
    """
    # If we care about more than just the temp data, we can extend this
    # logic with ``elif``. If the XML gets really hairy, we can create a
    # ``dict`` of handler functions and index it by tag name, e.g.,
    # { 'humidity': humidity_handler }
    if 'temp_c' == name:
        print "The current temperature is %(data)s degrees Celsius." % attrs

def process_weather_conditions():
    """
    Main logic of the POC; set up the parser and handle resource
    cleanup.
    """
    my_parser = expat.ParserCreate()
    my_parser.StartElementHandler = start_element_handler

    # I don't know if the S60 supports try/finally, but that's not
    # the point of the POC.
    try:
        f = urllib.urlopen("http://www.google.com/ig/api?weather=30096")
        my_parser.ParseFile(f)
    finally:
        f.close()

if __name__ == '__main__':
    process_weather_conditions()