如何更改 Groupby 生成的 plot 中的 x 轴标签

Question

I want to replace the current x-axis label to the label shown below:
labels = ["Oct","Nov","Dec", "Jan", "Feb", "Mar", "April", "May", "June", "July"]

The code I've used to generate the plot is:

df.groupby(pd.Grouper(key='Date', freq='1M')).sum().plot.bar(legend=False)

The output that I got is shown below, here you can see the x-axis have label as dates.

How I can replace those labels with Month names?

Answer 1

First generate your groupby result:

tbl = df.groupby(pd.Grouper(key='Date', freq='M')).sum()

Then change the index from "full" dates into abbreviated month names:

tbl.set_index(tbl.index.month_name().rename('Month').map(lambda tt: tt[:3]), inplace=True)

And finally draw your figure:

tbl.plot.bar(legend=False);

Note the trailing ; to prevent from additional display concerning the type of the created object.

Answer 2

You could have a look atDate formatters . There exists DateFormatter class which accepts a fmt argument which is a strftime format string.

Here is a reference of strftime() and strptime() format codes.

To format as month abbreviated name, you need to use %b .

import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as mdates

ax = df.groupby(pd.Grouper(key='Date', freq='1M')).sum().plot.bar(legend=False)

ax.xaxis.set_major_formatter(mdates.DateFormatter(fmt='%b'))

plt.show()