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python-3.xpandaskmlsimplekml

How to create a .kml file from a dataframe?

I need to create a .kml file from a dataframe with more than 800 districts. This is what I have done so far:

1) Read a .csv file (FIG 1) using PANDAS

2) Creat a new dataframe by choosing only the first 3 columns (longitude, latitude, altitude)

3) Create a list of tuples from the dataframe

4) Create a .kml file and do some styling (colors)

All this proceure work great ONLY when there is 1 district. Now I need to do the same but with more than 800 districts. In FIG 2, it is shown an example with 2 districts (ACTONO and AILSACRAIGO).

When converting the dataframe to a list of tuples, how can make "python" know that there are many districts?

I believe these lines have to be improved:

a) Here I will need a list of tuples (one for each district)

#Converting the dataframe to a list of tuples
tuples = [tuple(x) for x in df_modify.values]

b) And here, "outboundaryies" will have to change for each of the tuples

pol = kml.newpolygon(name= 'ACTONO', description= 'Acton County', 
outerboundaryis=tuples, extrude=extrude, altitudemode=altitudemode)

This is all the code:

CODE FOR .CSV WITH 1 DISTRICT

import pandas
import simplekml

kml = simplekml.Kml()

#Using PANDAS to read .csv and chosing the first 3 columns
df = pandas.read_csv('C:\\Users\\disa_ONTshp.csv')
df_modify=df.iloc[:, [0,1,2]]

#Converting the dataframe to a list of tuples
tuples = [tuple(x) for x in df_modify.values]


#Creating a .kml file
extrude=1
altitudemode = simplekml.AltitudeMode.relativetoground
pol = kml.newpolygon(name= 'ACTONO', description= 'Acton County', 
outerboundaryis=tuples, extrude=extrude, altitudemode=altitudemode)

#Styling colors
pol.style.linestyle.color = simplekml.Color.green
pol.style.linestyle.width = 5
pol.style.polystyle.color = simplekml.Color.changealphaint(100, 
simplekml.Color.green)

#Saving
kml.save("Polygon Styling.kml")

FIG 1 (1 DISTRICT)

FIG 1

FIG 2 (2 DISTRICTS)

CSV file

Solution

  • This is the answer. What I needed was a dictionary of dataframes.

    import pandas as pd
import simplekml
import pprint
import numpy as np


kml = simplekml.Kml()

###LOADING THE .csv FILE WITH ALL THE COORDINATES (USING QGIS)
df = pd.read_csv('C:\\Users\\file.csv')



###ADDING A COLUMN "altitude" WITH RANDOM VALUES FROM 200 TO 2000
df['altitude']=df.groupby('name').name.transform(lambda x: np.random.randint(200,2000))

###CALLING THE COLUMNS OF INTEREST
df=df[['longitude', 'latitude', 'altitude', 'name']]



###CREATING A DICTIONARY OF DATAFRAMES (ONE FOR EACH DISTRICT) 
dict_dataframes=dict(tuple(df.groupby('name')))


###CALLING EACH DATAFRAME FROM THE DICTIONARY
for name, df in dict_dataframes.items():


    ###CREATING A LIST OF TUPLES WITH THE COLUMNS OF THE DATAFRAME
    tuples = [tuple(x) for x in df.values]


    extrude=1
    altitudemode = simplekml.AltitudeMode.relativetoground

    pol = kml.newpolygon(name = name, description="District of " + name, outerboundaryis=tuples, extrude=extrude, altitudemode=altitudemode)
    pol.style.linestyle.color = simplekml.Color.honeydew
    pol.style.linestyle.width = 3
    pol.style.polystyle.color = simplekml.Color.changealphaint(100, simplekml.Color.navy)


###SAVING THE FILE    
kml.save('C:\\Users\\3d_file.kml')