Horizontal box plots in matplotlib/Pandas

matplotlib has a vert property which is set to True by default. Change it to False

plt.boxplot(df["feature"], vert=False)

vert=False stands # for "no vertical"

Use by='categorical_feature name' to make box for every level plt.tight_layout() # kills any overlapping plots (not always) Matplotlib and Pandas are really easy when you master them and you can do powerful plots using them.

matplotlib's boxplot(..., vert=False) makes horizontal box plots. The keyword parameter vert=False can also be passed to DataFrame.boxplot:

import matplotlib.pyplot as plt
import pandas as pd
x = [[1.2, 2.3, 3.0, 4.5],
     [1.1, 2.2, 2.9, 5.0]]
df = pd.DataFrame(x, index=['Age of pregnant women', 'Age of pregnant men'])

df.T.boxplot(vert=False)
plt.subplots_adjust(left=0.25)
plt.show()

I see from the comment (below) that the motivation for making a horizontal box plot is that the labels are rather long. Another option in that case might be to rotate the xticklabels:

import matplotlib.pyplot as plt
import pandas as pd
x = [[1.2, 2.3, 3.0, 4.5],
     [1.1, 2.2, 2.9, 5.0]]
df = pd.DataFrame(x, index=['Age of pregnant women', 'Age of pregnant men'])

df.T.boxplot()
plt.subplots_adjust(bottom=0.25)
plt.xticks(rotation=25)
plt.show()