Python之Folium Choropleth map之颜色不正确

我的问题是郊区在 Folium map 上显示的颜色不正确。例如，Dandenong 和 Frankston 应该用最深的颜色着色，因为它们在数据框中的计数最高，但它们用较浅的颜色着色。

数据框缺少一些郊区。那些郊区被涂上了最深的颜色。

另一个问题是 csv 的所有郊区都是大写的，但 geojson 混合了大小写，例如“Frankston”、“St Kilda”或“McKinnon”。如果 choropleth 代码不关心大小写，那将会很有帮助。我可以更改数据框中的文本以制作“FRANKSTON”、“Frankston”和“ST KILDA”、“St Kilda”，但是“MCKINNON”到“McKinnon”有点棘手。

创建数据框

import csv  
import pandas as pd 
csv_path='Data_tables_Criminal_Incidents_Visualisation_year_ending_June_2018.csv' 
df=pd.read_csv(csv_path) 
 
with open(csv_path, 'r') as csvfile:  
    # creating a csv reader object  
    csvreader = csv.reader(csvfile)  
    # create a list of headings from the first row of the csv file 
    headings = next(csvreader) 
 
# create a dictionary, where keys are Suburb/Town Name and values are number of occurences 
# index 2 of the headings list are the suburbs 
neighborhood_dict = df[headings[2]].value_counts().to_dict() 
 
# make first letter uppercase eg St Kilda 
neighborhood_dict = dict((k.title(), v) for k, v in neighborhood_dict.items()) 
 
 
# make neighborhood_list from neighborhood_dict 
neighborhood_list=[] 
for key, value in neighborhood_dict.items(): 
    temp = [key,value] 
    neighborhood_list.append(temp) 
 
# make dataframe from neighborhood_list 
df = pd.DataFrame(neighborhood_list, columns=['Suburb','Count']) 
 
print(df.to_string())  

创建 map

import folium 
 
world_map = folium.Map( 
        location=[-38.292102, 144.727880], 
        zoom_start=6, 
        tiles='openstreetmap' 
        ) 
 
world_map.choropleth( 
        geo_data='vic.geojson', 
        data=df, 
        columns=['Suburb','Count'], 
        key_on='feature.properties.Suburb_Name', 
        fill_color='YlOrRd', 
        fill_opacity=0.7, 
        line_opacity=0.2, 
        legend_name='Crime Rate in Victoria' 
        ) 
 
world_map.save('index.html') 

请您参考如下方法:

我想通了。缺失值是灰色的，图例是用我选择的间隔定制的。清理 geojson，删除尾随空格，并使所有郊区名称大写解决了很多问题。

Files are here

创建字典

import pandas as pd 
import csv  
 
csv_path='Data_tables_Criminal_Incidents_Visualisation_year_ending_June_2018.csv' 
df=pd.read_csv(csv_path) 
 
# sum the number of incidents recorded for each suburb 
df=df.groupby(['Suburb/Town Name'])['Incidents Recorded'].agg( 
    # make the numbers numeric otherwise it just concatenates strings 
    lambda x: pd.to_numeric(x, errors='coerce').sum() 
) 
 
# create a dictionary, where keys are Suburb/Town Name and values are number of incidents 
suburb_dict = df.to_dict() 

样式函数

def style_function(feature): 
    suburb = suburb_dict.get(feature['properties']['Suburb_Name']) 
    return { 
        'fillColor': '#gray' if suburb is None else colormap(suburb), 
        'fillOpacity': 0.6, 
        #borders 
        'weight': 0.2, 
    } 

叶子 map

import folium 
 
world_map = folium.Map( 
        location=[-38.292102, 144.727880], 
        zoom_start=6, 
        tiles='openstreetmap' 
        ) 
 
folium.GeoJson( 
    data = 'vic_for_crime_2018.geojson', 
    style_function = style_function     
).add_to(world_map) 

色图

import branca 
 
colormap = branca.colormap.linear.YlOrRd_09.scale(0, 8500) 
colormap = colormap.to_step(index=[0, 1000, 3000, 5000, 8500]) 
colormap.caption = 'Incidents of Crime in Victoria (year ending June 2018)' 
colormap.add_to(world_map) 
 
world_map.save('vic_final.html')