topic Re: import Pandas DataFrame with Polyline field using Python API in ArcGIS API for Python Questions

import Pandas DataFrame with Polyline field using Python API

Jay_Gregory — Fri, 10 Feb 2017 17:06:09 GMT

Been playing around with the Python API. I'm using a Pandas dataframe, to which I've added a column that has a Polyline (arcgis.geometry.Polyline class) as it's attribute. I would like to add this dataframe to a map, but the import_data method only seems to work on dataframes with x,y or lat,long column names, and I couldn't find a way to specify the Shape field when invoking the method. Is this possible?

My code, in general, looks like:

fc_lines = gis.content.import_data(df_lines)

map1 = gis.map()
map1.add_layer(fc_lines)

df_lines is a dataframe with a column, named "Lines" that contains an arcgis.geometry.Polyline object. At least I think it contains an object - when I print out the dataframe, that column has something like

{"paths": [[32.08138, 40.17111], [35.182777, 39.4016666]], "spatialReference": {"wkid": 4326}}

which is the string representation of the object. But if it's actually stored as a string, that's a different matter (and maybe why it won't work).

Is there a way to do what I want using the Python API, or should I somehow export the dataframe to a feature class, if that's even possible.

Re: import Pandas DataFrame with Polyline field using Python API

JillKelly — Tue, 21 Feb 2017 15:44:50 GMT

If you actually have a polyline geometry, try following it with

lines = arcgis.features.Feature(fc_lines)
lines1 = arcgis.features.FeatureSet([lines])

and then

map1.draw(lines1) instead of add_layer.

If not, to get from the text string to a geometry, you'd need

fc_lines = arcgis.geometry.Polyline(fc_string_thing)

before all that.

Hope this works; I got it working for pandas-dataframe-to-polygon.

Re: import Pandas DataFrame with Polyline field using Python API

Jay_Gregory — Fri, 24 Feb 2017 20:20:57 GMT

I would love to see a code example if you have one. I could not get this to work. I am able to create a FeatureSet made up of Features (the feature is of type "Polyline"), but I can't pass the FeatureSet into draw (I believe the function only takes one item to draw, not a list). And even if I pass in a single Feature, the map refreshes, but I don't see any graphics...

#lines1 = features.FeatureSet(features = df_lines['Lines'])

map1 = gis.map()
symbol = {
   "type": "esriSLS",
   "style": "esriSLSSolid",
   "color": [115,76,0,255],
   "width": 3
}

for item in df_lines['Lines']:
print("drawing " + str(item.geometry))
map1.draw(shape = item.geometry, symbol=symbol)
map1

At the very least, I can't even get this simple example to work: can you?

my_line = arcgis.geometry.Polyline({"paths": [[38.8,-78.8],[34.2,-117]]})
my_line_feature = arcgis.features.Feature(my_line, attributes=None)

map1.draw(my_line, symbol=symbol)

map1.draw(my_line_feature, symbol=symbol)

Re: import Pandas DataFrame with Polyline field using Python API

Jay_Gregory — Fri, 24 Feb 2017 20:42:05 GMT

Even though I mixed up x and y, it still won't work

Re: import Pandas DataFrame with Polyline field using Python API

JillKelly — Sat, 25 Feb 2017 22:56:53 GMT

Much stripped down, this works:

my_line_geom = {'paths' : [[[-78.8,38.8],[-78.8,38.2]]]}
my_line = arcgis.geometry.Polyline(my_line_geom)
my_line_feature = arcgis.features.Feature(my_line)
my_line_feature_set = arcgis.features.FeatureSet([my_line_feature])
map1 = gis.map('Orkney Springs')
map1.draw(my_line_feature_set)
map1

I have not been able to draw both features of a two-feature feature set. Only the second one shows up. Nor have I had any success setting the symbology.

Re: import Pandas DataFrame with Polyline field using Python API

Jay_Gregory — Mon, 27 Feb 2017 15:58:38 GMT

Thanks - so it seems like Esri still has some work to do on this API....