Python find distance between geolocation in dataframe having same id

Question

I have a pandas dataframe with duplicate site Ids and longitude and latitude I want to find the distance between the locations of these sites so that if they are away by more than 2 miles I can mark that they are different locations

id	Longitude	Latitude
1	35.624404	34.542616
2	35.637812	34.52873
3	35.433423	34.465716
1	35.439104	34.468755
2	35.512096	34.524426
3	35.512096	34.524426

Answer 1

This can be done fully in geopandas

• use UTM CRS so that distances are meaningful. Note this will calculate distance in meters, hence conversion factor to miles of 1609.34
• so you know which point (first point in group) has been used as reference, the index of this point in original data frame is captured
• this solution will work if there are 1, 2 or more points that share the same id

import pandas as pd
import geopandas as gpd

# sample data
df = pd.DataFrame(
    **{
        "columns": ["id", "Longitude", "Latitude"],
        "data": [
            [1, 35.624404, 34.542616],
            [2, 35.637812, 34.52873],
            [3, 35.433423, 34.465716],
            [1, 35.439104, 34.468755],
            [2, 35.512096, 34.524426],
            [3, 35.512096, 34.524426],
        ],
    }
)

gdf = gpd.GeoDataFrame(
    df["id"],
    geometry=gpd.points_from_xy(df["Latitude"], df["Longitude"]),
    crs="epsg:4386",
)
gdf = gdf.to_crs(gdf.estimate_utm_crs())

# for each id, calculate distance in miles from first point
# for good measure capture index of point used to calc distance
gdf = (
    gdf.groupby("id")
    .apply(
        lambda d: d.assign(
            d=d["geometry"].distance(d["geometry"].iat[0]) / 1609.34,
            i=d.index.values[0],
        )
    )
    .to_crs("epsg:4326")
)

gdf

output

	id	geometry	d	i
0	1	POINT (34.542616 35.624404000000006)	0	0
1	2	POINT (34.52873 35.637812)	0	1
2	3	POINT (34.465716 35.433423)	0	2
3	1	POINT (34.468755 35.439104)	13.4336	0
4	2	POINT (34.524426 35.512096)	8.66908	1
5	3	POINT (34.524426 35.512096)	6.35343	2