Plotting categorical data with pandas and matplotlib

Question

I have a data frame with categorical data        colour  direction 1    red     up 2    blue    up 3    green   down 4    red     left 5    red     right 6    yellow  down 7    blue    down   I want to generate some graphs  like pie charts and histograms based on the categories  Is it possible without creating dummy numeric variables  Something like  df plot kind  hist

User · Answer

To plot multiple categorical features as bar charts on the same plot, I would suggest:

import pandas as pd
import matplotlib.pyplot as plt

df = pd.DataFrame(
    {
        "colour": ["red", "blue", "green", "red", "red", "yellow", "blue"],
        "direction": ["up", "up", "down", "left", "right", "down", "down"],
    }
)

categorical_features = ["colour", "direction"]
fig, ax = plt.subplots(1, len(categorical_features))
for i, categorical_feature in enumerate(df[categorical_features]):
    df[categorical_feature].value_counts().plot("bar", ax=ax[i]).set_title(categorical_feature)
fig.show()

User · Answer

You can simply use value counts on the series   df  colour   value counts   plot kind  bar

User · Answer

You can simply use value counts with sort option set to False  This will preserve ordering of the categories df  colour   value counts sort False  plot bar rot 0

User · Answer

You could also use countplot from seaborn   This package builds on pandas to create a high level plotting interface  It gives you good styling and correct axis labels for free   import pandas as pd import seaborn as sns sns set    df   pd DataFrame   colour     red    blue    green    red    red    yellow    blue                        direction     up    up    down    left    right    down    down     sns countplot df  colour    color  gray       It also supports coloring the bars in the right color with a little trick  sns countplot df  colour                  palette  color  color for color in df  colour   unique

User · Answer

You might find useful mosaic plot from statsmodels  Which can also give statistical highlighting for the variances   from statsmodels graphics mosaicplot import mosaic plt rcParams  font size     16 0 mosaic df    direction    colour         But beware of the 0 sized cell - they will cause problems with labels   See this answer for details

User · Answer

like this     df groupby  colour   size   plot kind  bar

[python] Plotting categorical data with pandas and matplotlib

Examples related to python

Examples related to pandas