Geopy，熊猫，FOR 循环失败答案

【问题标题】：Geopy, pandas, FOR loop failGeopy，熊猫，FOR 循环失败
【发布时间】：2021-03-02 15:28:50
【问题描述】：

我正在自学geopy。看起来简单明了，但我的代码不起作用。它应该：

将地址字段列表从 CSV 读入 pandasdf
将地址字段连接成一个格式为geopy 的列
从新列中列出一个列表
通过for循环将列表中的每个项目输入geopy并返回坐标添加坐标到原始 df 并将其导出为 CSV

    #setup
    from geopy.geocoders import Nominatim
    import pandas as pd
        
    #create the df
    df = pd.DataFrame(pd.read_csv('properties to geocode.csv'))
    df['Location'] = df['Street Address'].astype(str)+","+df['City'].astype(str)+","+df['State'].astype(str)
        
    #create the geolocator object
    geolocator = Nominatim(timeout=1, user_agent = "My_Agent")
        
    #create the locations list
    locations = df['Location']
        
    #empty lists for later columns
    lats = []
    longs = []
        
    #process the location list
    for item in locations: 
        location = geolocator.geocode('item')
        lat =  location.latitude
        long = location.longitude
        lats.append(lat)
        longs.append(long)
        
    #add the lists to the df
    df.insert(5,'Latitude',lats)
    df.insert(6,'Longitude',longs)
        
    #export
    df.to_csv('geocoded-properties2.csv',index=False)

有些东西不起作用，因为它为每一行返回相同的纬度和经度值，而不是每行的唯一坐标。

我在其他地方找到了使用 .apply 的工作代码，但我有兴趣了解我做错了什么。有什么想法吗？

【问题讨论】：

location = geolocator.geocode('item') 您传递的是字符串文字，而不是变量 item 的值
感谢您的回复。当我删除项目周围的“”时，出现以下错误：AttributeError：“NoneType”对象没有属性“纬度”
我提供了更广泛的答案。如果您提供的地址未找到geolocator.geocode()，则返回None。这是我在返回之前编写的函数中明确测试过的

标签： python-3.x pandas for-loop geopy

【解决方案1】：

您的代码不包含示例数据。使用了一些来自公共 API 的示例数据来演示
您的代码将文字传递给geolocator.geocode() - 它必须是与行关联的地址
提供了使用 pandas apply、列表推导 和 for 循环等价于理解的示例
结果表明所有三种方法都是等效的

from geopy.geocoders import Nominatim
import requests
import pandas as pd

searchendpoint = "https://directory.spineservices.nhs.uk/ORD/2-0-0/organisations"
# get all healthcare facilities in Herefordshire
dfhc = pd.concat([pd.json_normalize(requests
                             .get(searchendpoint, params={"PostCode":f"HR{i}","Status":"Active"})
                             .json()["Organisations"]) 
           for i in range(1,10)]).reset_index(drop=True)

def gps(url, geolocator=None):
    # get the address and construct a space delimted string
    a = " ".join(str(x) for x in requests.get(url).json()["Organisation"]["GeoLoc"]["Location"].values())
    lonlat = geolocator.geocode(a)
    if not lonlat is None:
        return lonlat[1]
    else:
        return (0,0)

# work with just GPs
dfgp = dfhc.loc[dfhc.PrimaryRoleId.isin(["RO180","RO96"])].head(5).copy()

geolocator = Nominatim(timeout=1, user_agent = "My_Agent")


# pandas apply
dfgp["lonlat_apply"] = dfgp["OrgLink"].apply(gps, geolocator=geolocator)

# list comprehension
lonlat = [gps(url, geolocator=geolocator) for url in dfgp["OrgLink"].values]
dfgp["lonlat_listcomp"] = lonlat

# old school loop
lonlat = []
for item in dfgp["OrgLink"].values:
    lonlat.append(gps(item, geolocator=geolocator))
dfgp["lonlat_oldschool"] = lonlat

	Name	OrgId	Status	OrgRecordClass	PostCode	LastChangeDate	PrimaryRoleId	PrimaryRoleDescription	OrgLink	lonlat_apply	lonlat_listcomp	lonlat_oldschool
7	AYLESTONE HILL SURGERY	M81026002	Active	RC2	HR1 1HR	2020-03-19	RO96	BRANCH SURGERY	https://directory.spineservices.nhs.uk/ORD/2-0-0/organisations/M81026002	(52.0612429, -2.7026047)	(52.0612429, -2.7026047)	(52.0612429, -2.7026047)
9	BARRS COURT SCHOOL	5CN91	Active	RC2	HR1 1EQ	2021-01-28	RO180	PRIMARY CARE TRUST SITE	https://directory.spineservices.nhs.uk/ORD/2-0-0/organisations/5CN91	(52.0619209, -2.7086105)	(52.0619209, -2.7086105)	(52.0619209, -2.7086105)
13	BODENHAM SURGERY	5CN24	Active	RC2	HR1 3JU	2013-05-08	RO180	PRIMARY CARE TRUST SITE	https://directory.spineservices.nhs.uk/ORD/2-0-0/organisations/5CN24	(52.152405, -2.6671942)	(52.152405, -2.6671942)	(52.152405, -2.6671942)
22	BELMONT ABBEY	5CN16	Active	RC2	HR2 9RP	2013-05-08	RO180	PRIMARY CARE TRUST SITE	https://directory.spineservices.nhs.uk/ORD/2-0-0/organisations/5CN16	(52.0423056, -2.7648698)	(52.0423056, -2.7648698)	(52.0423056, -2.7648698)
24	BELMONT HEALTH CENTRE	5CN22	Active	RC2	HR2 7XT	2013-05-08	RO180	PRIMARY CARE TRUST SITE	https://directory.spineservices.nhs.uk/ORD/2-0-0/organisations/5CN22	(52.0407746, -2.739788)	(52.0407746, -2.739788)	(52.0407746, -2.739788)

【讨论】：