python-3.x - PathCollection' 对象没有属性 legend_elements''

Question

我知道有人问过这个确切的问题 here ，但是当前的解决方案对我没有任何作用。我似乎无法为每个标签生成一个具有不同颜色的图例。我已经尝试了 Matplotlib 上的当前文档无济于事。我不断收到我的 PathCollection object has no attribute legend_elements 的错误

编辑:另外，我希望我的传奇只是 Years ，情节的独特年份而不是现在的情况是每个数据点都映射到我的图例。
这是我所拥有的

import numpy as np # linear algebra
import pandas as pd # data processing, CSV file I/O (e.g. pd.read_csv)
import matplotlib.pyplot as plt
from matplotlib.pyplot import figure
from matplotlib.pyplot import legend
import os

%config InlineBackend.figure_format = 'retina'

path = None
for dirname, _, filenames in os.walk('/kaggle/input'):
    for filename in filenames:
        path = os.path.join(dirname, filename)

# Indexes to be removed
early_demo_dividend = 13
high_income = 24
lower_middle_income = 40
north_america = 46
members = 50
post_demo = 56
_removals = [early_demo_dividend, high_income, lower_middle_income, north_america, members, post_demo]

#Read in data
df = pd.read_csv(path)

#Get the rows we want
df = df.loc[df['1960'] > 1]
df = df.drop(columns=["Code", "Type", "Indicator Name"])

#Remove the odd rows
for i in _removals:
    df = df.drop(df.index[i])

#Format the dataframe
df = df.melt('Name', var_name='Year', value_name='Budget')

#Plot setup
plt.figure().set_size_inches(16,6)
plt.xticks(rotation=90)
plt.grid(True)

#Plot labels
plt.title('Military Spending of Countries')
plt.xlabel('Countries')
plt.ylabel('Budget in Billions')

#Plot data
new_year = df['Year'].astype(int)
scatter = plt.scatter(df['Name'], df['Budget'], c=(new_year / 10000) , label=new_year)

#Legend setup produce a legend with the unique colors from the scatter
legend1 = plt.legend(*scatter.legend_elements(),
                    loc="lower left", title="Years")
plt.add_artist(legend1)

plt.show()

这是我的情节

Answer 1

我也遇到了这个问题。

尝试升级您的 matplotlib与 pip3 install --upgrade matplotlib

    Uninstalling matplotlib-3.0.3:
      Successfully uninstalled matplotlib-3.0.3
Successfully installed matplotlib-3.1.2

这个对我有用。