Python 从返回最大值和关联数据的列表中删除数据

从上面我想找到最东部和最北部的城市。所以我想解析最大经度或纬度，然后返回城市和国家。以下是我的第一次努力，但显然不起作用，因为我不知道如何解决这个问题。我66岁了，所以没有做作业，只是想看看我的大脑是否还能工作！谢谢你的帮助

[['Albania', 'Tirana', '41.3289', '19.8178'],
 ['Andorra', 'Andorra la Vella', '42.5000', '1.5000'],
 ['Austria', 'Vienna', '48.2000', '16.3667'],
 ['Belarus', 'Minsk', '53.9000', '27.5667'],
 ['Belgium', 'Brussels', '50.8500', '4.3500'],
 ['Bosnia and Herzegovina', 'Sarajevo', '43.8667', '18.4167'],
 ['Bulgaria', 'Sofia', '42.7000', '23.3300'],
 ['Croatia', 'Zagreb', '45.8167', '15.9833'],
 ['Czech Republic', 'Prague', '50.0833', '14.4167'],
 ['Denmark', 'Copenhagen', '55.6761', '12.5683'],
 ['Estonia', 'Tallinn', '59.4372', '24.7453'],
 ['Finland', 'Helsinki', '60.1708', '24.9375'],
 ['France', 'Paris', '48.8567', '2.3508'],...]

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我认为问题在于lambda排序。纬度和经度是字符串，而不是整数或浮点数。例如，将长度排序为字符串：

def find_city():
    from operator import itemgetter
    eu_list=[]
    EU =['Austria','Belgium', 'Bulgaria','Czech Republic', 'Croatia', 'Cyprus','Denmark', 'Estonia', 'France', 'Finland', 'Germany', 'Hungary','Ireland', 'Italy', 'Luxembourg', 'Latvia', 'Lithuania', 'Malta','Netherlands', 'Portugal', 'Poland', 'Romania', 'Spain', 'Sweden','Slovakia', 'Slovenia','United Kingdom']
    countrylist =parse_doc()
    #print(countrylist)

    for item in countrylist:
        country   = item[0]
        capital   = item[1]
        latitude  = item[2]
        longitude = item[3]

        if country in EU:
            eu_list.append(item)
            #print("{} is the capital of {} and is at {} north and {} east".format(capital,country, latitude, longitude))    
        #else: #item[0] not in EU:
            #print("{} is the capital of {} and is at {} north and {} east, but is not in the EU".format(capital,country, latitude, longitude))    
    result = sorted(eu_list,key=lambda x: x[3], reverse=True)[3] #doesn't work
    result1= sorted(eu_list,key=lambda x: x[3], reverse=True)[2] #doesn't work
    print("{} in {} is the most eastern city in the EU".format(result[1], result[0]))
    print("{} in {} is the northern-most city in the EU".format(result1[1], result1[0]))

所以试试这个：

[
 '1.5000',
 '12.5683',
 '14.4167',
 '15.9833',
 '16.3667',
 '18.4167',
 '2.3508',
 '23.3300',
 '24.7453',
 '24.9375',
 '27.5667',
 '4.3500'
]

输出：

result = sorted(eu_list,key=lambda x: float(x[3]), reverse=True)[0] # longitude sorted
result1= sorted(eu_list,key=lambda x: float(x[2]), reverse=True)[0] # latitude sorted

您的正确代码：

Helsinki in Finland is the most eastern city in the EU
Helsinki in Finland is the northern-most city in the EU

---

不需要对列表进行排序就可以找到larges元素

result = sorted(eu_list,key=lambda x: x[3], reverse=True)[0] #x[3] is the longitude that you want to compare, and the last [0] point to the first element of the sorted list
result1= sorted(eu_list,key=lambda x: x[2], reverse=True)[0] #x[2] is the latitude that you want to compare
print("{} in {} is the most eastern city in the EU".format(result[1], result[0]))
print("{} in {} is the northern-most city in the EU".format(result1[1], result1[0]))

---

这是一个更快的算法，我认为它看起来也更简单。

谢谢您的帮助。这似乎适用于格子，但不适用于经度，从完整的列表中，我认为赫尔辛基是最北部，但我认为卢森堡是最东部的wheras，应该是布加勒斯特（我的列表中没有塞浦路斯，它应该是）。我相信这是我的错误，我的想法很有效。非常感谢。我可以在网上做一些练习来“掌握”排序吗？我不知道关于排序的确切情况，但我学过python。也许这就是你需要的。谢谢。我也要试试这个。

result = max(eu_list, key=lambda x: float(x[3]))
result1 = max(eu_list, key=lambda x: float(x[2]))
print("{} in {} is the most eastern city in the EU".format(result[1], result[0]))
print("{} in {} is the northern-most city in the EU".format(result1[1], result1[0]))