等值线图未显示答案

【问题标题】：choropleth map not showing等值线图未显示
【发布时间】：2020-04-29 07:11:06
【问题描述】：

我是 Python for Data Science 的新手，这是我在这里的第一个帮助请求（请为一些错误提前道歉）。需要您的支持才能了解为什么此（基于简单数据框的）等值线图未显示。阅读了很多关于该论点的讨论，然后我验证了所有主要内容：str 等中的地区名称和 NAAM（在 geojson 中） - 但我仍然卡住了，我看不到地图（只有图例）。让我知道是否需要更多信息，您可以在下面找到代码：在[9]中：

df_clo=dfrc.groupby(['District']).mean()
df_clo.reset_index(inplace=True)
df_clo=df_clo[['District','Rent']]
df_clo['District'] = df_clo['District'].str.upper()
df_clo

输出[9]：

District    Rent
0   BINNENSTAD  1792.281250
1   NOORDOOST   1763.558824
2   OOST    1739.186047
3   ZUID    1562.142857
4   ZUIDWEST    1397.689655

在[10]中：

latitude = 52.09083
longitude = 5.12222
print('The geograpical coordinate of Utrecht are {}, {}.'.format(latitude, longitude))# create map of Utrecht using latitude and longitude values
utrecht_geo = r'https://raw.githubusercontent.com/umbesallfi/Coursera_Capstone/master/wijk_.geojson'
# create a numpy array of length 6 and has linear spacing from the minium total immigration to the maximum total immigration
threshold_scale = np.linspace(df_clo['Rent'].min(),
                              df_clo['Rent'].max(),
                              6, dtype=int)
threshold_scale = threshold_scale.tolist() # change the numpy array to a list
threshold_scale[-1] = threshold_scale[-1] + 1 # make sure that the last value of the list is greater than the maximum immigration
# let Folium determine the scale.
map_utr = folium.Map(location=[latitude, longitude], zoom_start=2, tiles='Mapbox Bright')
map_utr.choropleth(
    geo_data=utrecht_geo,
    data=df_clo,
    columns=['District', 'Rent'],
    key_on='feature.properties.NAAM',
    threshold_scale=threshold_scale,
    fill_color='YlOrRd', 
    fill_opacity=0.7, 
    line_opacity=0.2,
    legend_name='Price in Utrecht by Wijk',
    reset=True
)
map_utr

【问题讨论】：

标签： python python-3.x geojson folium choropleth

【解决方案1】：

wijk_.geojson 文件中的区名不以正楷存储。因此，删除这一行就足够了：

df_clo['District'] = df_clo['District'].str.upper()

我的代码：

import folium
import pandas as pd
import numpy as np

m = folium.Map(location=[52.09083, 5.12222],
               zoom_start=12,
               control_scale=True)

df_clo = pd.DataFrame({'District':['Binnenstad','Noordoost','Oost','Zuid','Zuidwest'],
                       'Rent':[1792.281250,
                               1763.558824,
                               1739.186047,
                               1562.142857,
                               1397.689655]})

threshold_scale = np.linspace(df_clo['Rent'].min(),
                              df_clo['Rent'].max(),
                              6, dtype=int)
threshold_scale = threshold_scale.tolist() # change the numpy array to a list
threshold_scale[-1] = threshold_scale[-1] + 1 # make sure that the last value of the list is greater than the maximum immigration

utrecht_geo = 'wijk_.geojson'

folium.Choropleth(geo_data=utrecht_geo,
                  name='choropleth',
                  data=df_clo,
                  columns=['District', 'Rent'],
                  key_on='feature.properties.NAAM',
                  threshold_scale=threshold_scale,
                  fill_color='YlOrRd',
                  fill_opacity=0.7,
                  line_opacity=0.2,
                  legend_name='Price in Utrecht by Wijk',).add_to(m)

folium.LayerControl().add_to(m)

m

返回此地图：

【讨论】：

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