PathCollection' object has no attribute legend_elements'' - python-3.x

Question

I know this exact question has been asked here, however the current solution does nothing for me. I can't seem to generate a legend that has a different color for each label. I have tried the current documentation on Matplotlib to no avail. I keep getting the error that my PathCollection object has no attribute legend_elements
EDIT: Also, I want my legend to be just the Years, unique years for the plot not how it is right now with is that each data point is mapped to my legend.
Here's what I have
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()
Heres my plot

Answer 1

I also encountered this problem.
Try to upgrade your matplotlib with pip3 install --upgrade matplotlib
Uninstalling matplotlib-3.0.3:
Successfully uninstalled matplotlib-3.0.3
Successfully installed matplotlib-3.1.2
It works for me.

Answer 2

Despite the fact that my answer may not be relevant to the current question, I decided to leave it to describe my case - it might be useful to someone else:
When using matplotlib functions such as scatter or plot, incorrectly specify the name of some additional arguments, you can get the same error.
Example:
x = list(range(10))
y = list(range(10))
plt.scatter(x, y, labels='RESULT')
I get the error:
AttributeError: 'PathCollection' object has no property 'labels'
As it said in error message (but it is not obvious to an inattentive developer :) ):
the problem that I use labels instead of label