Geopy, pandas, FOR loop fail - python-3.x

Question

I am teaching myself geopy. It seems simple and straightforward yet my code isn't working. It is supposed to:
read in a list of address field from a CSV into a pandas df
concatenate the address fields into a single column formatted for geopy
make a list from the new column
feed each item in the list into geopy via a for loop and return the coordinates add the
coordinates to the original df and export it to a 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)
Something is not working because it returns the same latitude and longitude values for every row, instead of unique coordinates for each.
I have found working code using .apply elsewhere but am interested in learning what I did wrong. Any thoughts?

Answer 1

your code does not contain sample data. Have used some sample data available from public APIs to demonstrate
your code passes a literal to geolocator.geocode() - it needs to be the address associated with the row
have provided example of using with pandas apply, a list comprehension and a for loop equivalent of a comprehension
results show all three approaches are equivalent
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)