Get field names in attribute table with Python

Question

I have a geopackage file, with a layer called "MyLayer". Within this I have an attribute table with approx 20 attributes.

I can read in each attribute individually like:

import geopandas as gpd

geopkg = gpd.read_file('MyGeoPkg.gpkg', layer='MyLayer')
A = geopkg['AttributeA']

However, I have multiple GPKG files and they may have a different number of attributes, that may have different names.

I'd like to automatically get a list like:

listOfAttributes = ['AttributeA', 'AttributeB', 'AttributeC']

so I could then do:

for l in listOfAttributes:
    data = geopkg[l]

Is there a way of getting a list of the field names from the layer so I can iterate over them?

martinfleis · Accepted Answer · 2019-10-09T15:57:31.963

2

You effectively want to iterate over columns of GeoDataFrame, which you can get using geopkg.columns.

So assuming you don't want to iterate over geometry field:

for col in geopkg.columns.drop('geometry'):
    data = geopkg[col]

edited Oct 09 '19 at 15:57

answered Oct 08 '19 at 21:15

martinfleis

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Fiona.listlayers('MyGeoPkg.gpkg') returns the layer, which gives me 'MyLayer', it doesn't return me the attribute fields - unless I'm not using it as intended...? – GeoMonkey Oct 09 '19 at 13:48
1

Oh sorry, I got confused by your code. I will edit accordingly. – martinfleis Oct 09 '19 at 15:52
my variable 'listOfLayers' was confusing. Will change to 'listOfAttributes'. Accepting as answer because it was the first and keeps it within geopandas/fiona – GeoMonkey Oct 09 '19 at 16:23

score 1 · Answer 2 · answered Oct 09 '19 at 15:16

I found an answer here. There are several examples here, but this one works the best for my case:

source = ogr.Open('MyGeoPkg.gpkg')
layer = source.GetLayer()
schema = []
ldefn = layer.GetLayerDefn()
for n in range(ldefn.GetFieldCount()):
    fdefn = ldefn.GetFieldDefn(n)
    schema.append(fdefn.name)
print(schema)

Get field names in attribute table with Python

2 Answers2