从文本文件中读取逗号分隔值并使用 python 创建 geoJson 文件

Question

I am currently working on a Google Maps project. Here I would like to collect coordinates (multiple points/polygon) from users and extract those values and dynamically create a new geoJson file which I can then append to the primary geoJson file which loads on my map.

For example, a user uploads a file (contents below):

latitude, longitude
30.095319, -95.993581
30.096340, -95.993399
30.096015, -95.991854
30.095040, -95.992219

I want to be able to extract these coordinates and create the geoJson file below:

{
    "type": "Feature",
    "geometry": {
        "type": "Polygon",
        "coordinates": [
            [
                [
                    -95.972251,
                    30.091505,
                    0
                ],
                [
                    -95.970337,
                    30.091318,
                    0
                ],
                [
                    -95.970973,
                    30.092492,
                    0
                ],
                [
                    -95.972136,
                    30.09262,
                    0
                ]
            ]
        ]
    }
}

Answer 1

read the csv with csv , turn the rows into the list of lists that you want, build a python dictionary with all the fields that you want and put the list of lists where it needs to be, then write the dictionary out as JSON with json

import csv
import json

with open("path/to/the/uploaded/file.csv") as f:
    reader = csv.DictReader(f)
    coordinates = []
    for row in reader:
        coordinates.append([row["longitude"], row["latitude"], 0])

geo_json = {"type": "Feature", "geometry": {"type": "Polygon", "coordinates": []}}

geo_json["geometry"]["coordinates"].append(coordinates)

with open("path/where/you/want/to/save/to.json", "w") as f:
    json.dump(geo_json, f, indent=4)