CSV to Folium HeatMap

Question

I have a csv that contains numerous different Lat Longs in the exact format shown: 39.360611,-74.431877

Running the following code:

import csv
from folium import plugins

heatmap_map = folium.Map(location=[48, -102], zoom_start=3)

with open('geolocation.csv', "r") as f:
    reader = csv.reader(f)
    data = [[row[0], row[1]] for row in reader]
    print(data)

hm = plugins.HeatMap(data)
heatmap_map.add_children(hm)
f.close()

heatmap_map.save("heatmap.html") 

Gives me the following Output

[['39.360611', '-74.431877']]
Traceback (most recent call last):
  File "C:\Users\dge\Anaconda3\lib\site-packages\folium\utilities.py", line 59, in validate_location
    float(coord)
ValueError: could not convert string to float: '-'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File ".\heat.py", line 12, in <module>
    hm = plugins.HeatMap(data)
  File "C:\Users\dge\Anaconda3\lib\site-packages\folium\plugins\heat_map.py", line 67, in __init__
    for line in data]
  File "C:\Users\dge\Anaconda3\lib\site-packages\folium\plugins\heat_map.py", line 67, in <listcomp>
    for line in data]
  File "C:\Users\dge\Anaconda3\lib\site-packages\folium\utilities.py", line 63, in validate_location
    .format(coord, type(coord)))
ValueError: Location should consist of two numerical values, but '-' of type <class 'str'> is not convertible to float.

It seems as though python is recognizing the - symbol as a string rather than piece of negative number

Answer 1

When attempting various things, I found a Pandas Dataframe to be the best way to get the Data from CSV to heatmap. The Code looks like the following:

import folium
from folium import plugins
import pandas as pd

df = pd.DataFrame()
heatmap_map = folium.Map(location=[48, -102], zoom_start=3)

with open(r'geolocation.csv', "r") as f:
    df = df.append(pd.read_csv(f),ignore_index = True)
    df = df.dropna()

hm = plugins.HeatMap(df)
heatmap_map.add_child(hm)
f.close()

heatmap_map.save("heatmap.html")

Notice the dropna as for some reason it always had a blank line entered at the end and this solved the issues that would be hit when passing such information to the heatmap