如何使用和阻止某个位置的特定颜色(python)

Question

我正在试着用他们在Eurovision上的结果来绘制一张欧洲国家的地图。我有一个按钮来选择不同的国家(意大利，法国，葡萄牙，英国，等等)

例如，如果我选择查看瑞典的结果，我希望在地图上看到其他人根据色标给出的点数。我成功地做到了！

但我想要可视化瑞典，例如地图上的黑色，以更好地了解它在哪里，以及“符号的邻里效应”。

fig3 = go.Figure(data=go.Choropleth(
    locations=Euro_tr['Country_code'], # Spatial coordinates
    z = Euro_tr['Italy'], # Data to be color-coded
    locationmode = "ISO-3",
    colorbar_title = "Points donnés",
    text=Euro_tr['Country'],
   ))


fig3.update_layout(
    title_text = 'Score Eurovision',
    margin={"r":55,"t":55,"l":55,"b":55},
    height=500,
    geo_scope="europe" ,
 
    
)

#Make a button for each country
button=[]
for country in Euro_tr.columns[1:-1] :
    dico=dict (
                    label=country,
                    method="update",
                    args = [{'z': [ Euro_tr[country] ] }],)
    button.append(dico)

fig3.update_layout(
     updatemenus=[
        dict(
            buttons=button,
            
            
            
         y=0.9,
         x=0,
         xanchor='right',
         yanchor='top',
         active=0,
    ),
        ])

正如你在这个例子中看到的给瑞典的分数，我希望瑞典是一种特定的颜色，独立于其他国家，那些给了分的国家和那些没有给分的国家。

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感谢您的帮助！

Answer 1

我关注了@vestland的答案，通过使用fig.add_traces(go.Choropleth)，我成功地将我感兴趣的国家以一种颜色呈现给其他人

为了能够根据我感兴趣的国家/地区更改数据和跟踪，我使用streamlit和按钮。

import streamlit as st
import pandas as pd
import numpy as np
import plotly.express as px
import plotly.graph_objects as go 

# Creation of graphes for each country 
Graphes=[]
for country in Euro_tr.columns[1:-1] : #To pass each country 

    Graphe=go.Figure(data=go.Choropleth(
    locations=Euro_tr['Country_code'], # Spatial coordinates
    z = Euro_tr[country], # Data to be color-coded
    locationmode = "ISO-3",
    colorbar_title = "Points donnés",
    autocolorscale= False,
    colorscale="viridis",
    text=Euro_tr['Country'],
   ))
    
    # customisation : title according to the country and its points
    Graphe.update_layout(
    title_text = "Total :Points donnés à {fcountry} qui a remporté {fpoints} points".format(fcountry = country, fpoints = Eurovision_tot['Result_tot'][Eurovision_tot["Country"]==country].values[0]),
    margin={"r":55,"t":55,"l":55,"b":55},
    height=500,
    )
 )
    # block a specific zoom on the map ( scope "europe" isn't complete for eurovision countries xD!)
    Graphe.update_geos(
    center=dict(lon= 23, lat= 54),
    lataxis_range=[31.0529,-40.4296], lonaxis_range=[-24, 88.2421],
    projection_scale=3
    )
    
    # add trace for the specific country.
    Graphe.add_traces(go.Choropleth(locations=Country_df['Country_code'][Country_df["Country"]==country],
                            z = [1],
                            colorscale = [[0, col_swe],[1, col_swe]],
                            colorbar=None,
                            showscale = False))
    
    Graphes.append(Graphe)

#creation selectbox to select country
col12, col22 = st.beta_columns([0.2,0.8])   # I use columns to put the selector on a  side and the graph on other side 
Pays=list(Euro_tr.columns[1:-1]) # List containing country's name
Selection_Pays = col12.selectbox('',(Pays)) #create a multiple selector with the different countries as possible choice


# define action according to the selection.
for country in Pays :
        if Selection_Pays== country : #if country is selected
            col22.plotly_chart(Graphes[Pays.index(country)]) # plot the corresponding map.

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Answer 2

即使你已经使用px.express构建了你的choropleth地图，你仍然可以使用plotly.graph_objects和fig.add_traces(go.Choropleth)来添加一个跟踪，如下所示：

col_swe = 'Black'
fig.add_traces(go.Choropleth(locations=df_swe['iso_alpha'],
                            z = [1],
                            colorscale = [[0, col_swe],[1, col_swe]],
                            colorbar=None,
                            showscale = False)
              )

据我所知，不可能直接定义单个国家的单一颜色，这就是为什么我指定了z=[1]作为一个值，并指定了一个自定义比例colorscale = [[0, col_swe],[1, col_swe]]，以确保瑞典始终以“黑色”显示。

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代码：

import plotly.express as px
import plotly.graph_objects as go

df = px.data.gapminder().query("year==2007")
fig = px.choropleth(df, locations="iso_alpha",
                    color="lifeExp", # lifeExp is a column of gapminder
                    hover_name="country", # column to add to hover information
                    color_continuous_scale=px.colors.sequential.Plasma)

df_swe = df[df['country']=='Sweden']
col_swe = 'Black'

fig.add_traces(go.Choropleth(locations=df_swe['iso_alpha'],
                            z = [1],
                            colorscale = [[0, col_swe],[1, col_swe]],
                            colorbar=None,
                            showscale = False)
              )

f = fig.full_figure_for_development(warn=False)

fig.show()