Iterating through a GeoDataFrame

[Dmitriy Tarasov]

I am trying to iterate through a GeoDataFrame called incidents (that was created by reading the contents of a point shapefile using the GeoPandas read_file function; for every point in the old shapefile, the nearest node on a network needs to be found). The code is as follows:

import omsnx as ox

...

for incident in incidents:

    node_near_incident = ox.distance.nearest_nodes(graph_proj, incident.geometry.x, incident.geometry.y, return_dist=False)

    incident_nodes.append(node_near_incident) # each node to get appended into another GeoDataFrame

This (specifically, the line that begins with "node_near_incident...") throws the following error:

AttributeError: 'str' object has no attribute 'geometry'

Why does each line (correct me if the terminology is wrong) in a GeoDataFrame treated as a string object, and what is the correct syntax for iterating through a GeoDataFrame?

[Martin Fleischmann]

Iterating over geopandas.GeoDataFrame has exactly the same behaviour as iterating over pandas.DataFrame. I’d recommend checking their guide https://pandas.pydata.org/docs/user_guide/basics.html#iteration

Yours `for incident in incidents` gives you column names, not rows.You will need itertuples or iterrows. But in this specific case, it will be faster to loop over xy series.

```

x_coords = incidents.geometry.x

y_coords = incidents.geometry.y

for x, y in zip(x_coords, y_coords):

    node_near_incident = ox.distance.nearest_nodes(graph_proj, x, y, return_dist=False)

    incident_nodes.append(node_near_incident)

```

Note that this code is not tested :).

Martin

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[Dmitriy Tarasov]

Thanks! For my purposes, the following syntax seems to work:

 for index, row in GeoDataFrameName.iterrows():

  <do something>