Concat multiple shapefiles via geopandas

Question

I'm trying to combine multiple shapefiles by implementing the follwing:

import geopandas as gpd
import pandas as pd

for i in range(10,56):
    interesting_files = "/Users/m3105/Downloads/area/tl_2015_{}_arealm.shp".format(i)
    gdf_list = []
    for filename in sorted(interesting_files):
        gdf_list.append(gpd.read_file((filename)))
        full_gdf = pd.concat(gdf_list)

in which the directory /Users/m3105/Downloads/area has several shapefiles with such as tl_2015_01_arealm.shp, tl_2015_02_arealm.shp all the way up to tl_2015_56_arealm.shp. I'd like to combine all of these shapefiles and avoid repeating their headers. However, whenever I try concating the files using the code above, I get the following error:

ValueError: Null layer: u''

Normally, I'd know how to concat csv files together but I'm note sure how to concat shapefiles. I'd greatly appreciate any help

There seem to be several errors in your code to be able to run: `interesting_files` is a single string, so looping through it with `for filename in sorted(interesting_files):` will loop through the single characters of that filename. Further, the `pd.concat(gdf_list)` should be outside of the for loop. — joris, Feb 19 '18 at 22:15

score 21 · Accepted Answer · answered Feb 20 '18 at 07:18

I can't test this since I don't have your data, but you want something like this (assuming python 3):

from pathlib import Path
import pandas
import geopandas

folder = Path("/Users/m3105/Downloads/area")
shapefiles = folder.glob("tl_2015_*_arealm.shp")
gdf = pandas.concat([
    geopandas.read_file(shp)
    for shp in shapefiles
]).pipe(geopandas.GeoDataFrame)
gdf.to_file(folder / 'compiled.shp')

score 18 · Answer 2 · edited Feb 28 '21 at 00:30

18

If using pandas.concat like the answer of @Paul H, some geographical imformation such as coordinate reference system(crs) does not get preserved by default. But it worked when using the way like below:

import os
import geopandas as gpd
import pandas as pd

file = os.listdir("Your folder")
path = [os.path.join("Your folder", i) for i in file if ".shp" in i]

gdf = gpd.GeoDataFrame(pd.concat([gpd.read_file(i) for i in path], 
                        ignore_index=True), crs=gpd.read_file(path[0]).crs)

In this way, the geodataframe will have CRS as your need

edited Feb 28 '21 at 00:30

DrSnuggles

217
1
14

answered Aug 15 '19 at 15:18

lemon

181
1
4

2

I have large datasets and this worked very fast! – g123456k Dec 30 '21 at 06:23
1

That is so efficent! – icypy Mar 25 '22 at 05:19

score 1 · Answer 3 · answered May 16 '22 at 23:10

I've not enough rep to comment on last submission but after testing input files with differing CRS's,

gdf = gpd.GeoDataFrame(pd.concat([gpd.read_file(i) for i in path], 
                        ignore_index=True), crs=gpd.read_file(path[0]).crs)

should be

gdf = gpd.GeoDataFrame(pd.concat([gpd.read_file(i).to_crs(gpd.read_file(path[0]).crs) for i in path], 
                        ignore_index=True), crs=gpd.read_file(path[0]).crs)

Concat multiple shapefiles via geopandas

3 Answers3

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