How to create a stacked percentage bar graph from a dataframe with percentage values

Question

I have following dataframe:

Class     Percentage
class1    0.215854
class2    0.12871
class3    0.122787
class4    0.0680061
class5    0.0670523
class6    0.0826716
class7    0.309828
class8    0
class9    0

How can I create a stacked vertical bar graph where y goes from 0-100% and the percentage data is plotted? I would also like to add a legend with a color corresponding to a class.

Code I’ve tried:

df.T.plot(kind='bar',stacked=True)

results in error: TypeError: Empty 'DataFrame': no numeric data to plot

classgraph,texts = plt.bar(df["Percentage"],height=5) #added texts for later legend

gave error:

Traceback (most recent call last):

  File "<ipython-input-71-894dc447893f>", line 1, in <module>
    classgraph,texts = plt.bar(dataframe_plot["Percentage"],height=5)

ValueError: too many values to unpack (expected 2)

I read quite some posts on how to do this but I can’t seem to figure it out.

Asked By: Robvh

||

Source

Answer 1

Well, let’s say you have this dataframe

import pandas as pd
import seaborn as sns
sns.set_style("darkgrid")

data = {'Class': ['class1', 'class2', 'class3'],
        'mid-term': [345, 123, 74],
        'final':[235, 345, 632]}

df = pd.DataFrame(data)
df.head()


#    Class  mid-term    final
#0  class1  345       235
#1  class2  123       345
#2  class3  74        632

If you plot it, the results will be messy.

df.set_index('Class').T.plot(kind='bar', stacked=True)

In order to solve the problem, you need to calculate the percentage for each column. Then plot it.

df['mid-per'] = (df['mid-term'] / df['mid-term'].sum() * 100)
df['final-per'] = (df['final'] / df['final'].sum() * 100)

df.set_index('Class')[['mid-per', 'final-per']].T.plot(kind='bar', stacked=True)

Answered By: N. Arunoprayoch

How to create a stacked percentage bar graph from a dataframe with percentage values

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