Saving multiple figures to one pdf file in matplotlib

Question

I have a code that creates about 50 graphs based on groupby. The code looks like this:

import matplotlib.pyplot as plt
from matplotlib.backends.backend_pdf import PdfPages

with PdfPages('foo.pdf') as pdf:
   for i, group in df.groupby('station_id'):
       plt.figure()


fig=group.plot(x='year', y='Value',title=str(i)).get_figure()
pdf.savefig(fig)

This is saving only one figure, (the last one in my series) when I would like all of my figures to be stored into one pdf. Any help would be appreciated.

Answer 1

There is an indentation error in your code. Since your plotting command was not in the loop, it will only create the last plot.

import matplotlib.pyplot as plt
from matplotlib.backends.backend_pdf import PdfPages

with PdfPages('foo.pdf') as pdf:
   for i, group in df.groupby('station_id'):
       plt.figure()
       fig=group.plot(x='year', y='Value',title=str(i)).get_figure()
       pdf.savefig(fig)