If I have a DataFrame with a column 'Year' and another column 'Average temperature' and I want to represent them in a barplot to see if the global average temperature has risen over the last decades, how do you convert years to decades?

For example, between 1980 and 1989 I need it to be represented in x axis as 1980. For 1990 and 1999 as 1990, and so on.

Note that:

x axis = Year

y axis = Average temperature

Many thanks

CodePudding user response：

You can do this by,

1. Converting years to starting year of the decade
2. Then take average temperature for years of that decade

Code:

import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt

#Sample data. Replace it with your data.
df = pd.DataFrame([[2011,20],[2012,10],[2013,10],[2014,10],[2015,10],[2016,10],[2017,10],[2018,10],[2019,10],[2020,10],[2021,10],[2022,15]], columns=['year','temp'])
df['year'] = df['year'] - df['year'] % 10
df_decade = (df.groupby(['year']).mean().reset_index())
ax = sns.barplot(x="year", y="temp", data=df_decade)
plt.show()