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python - CSV 到 Folium 热图

问题描述

我有一个 csv，其中包含许多不同的经纬度，格式如下所示： 39.360611,-74.431877

运行以下代码：

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")

给我以下输出

[['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.

似乎python将 - 符号识别为字符串而不是负数

标签： pythonfolium

解决方案

在尝试各种事情时，我发现 Pandas Dataframe 是将数据从 CSV 获取到热图的最佳方式。代码如下所示：

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")

请注意，dropna由于某种原因，它总是在末尾输入一个空行，这解决了将此类信息传递给热图时会遇到的问题

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