Matplotlib graphic image to base64

import cStringIO
my_stringIObytes = cStringIO.StringIO()
plt.savefig(my_stringIObytes, format='jpg')
my_stringIObytes.seek(0)
my_base64_jpgData = base64.b64encode(my_stringIObytes.read())

[edit] in python3 it should be

import io
my_stringIObytes = io.BytesIO()
plt.savefig(my_stringIObytes, format='jpg')
my_stringIObytes.seek(0)
my_base64_jpgData = base64.b64encode(my_stringIObytes.read())

I think at least ... based on the documentation http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.savefig

For python 3

import base64
import io 
pic_IObytes = io.BytesIO()
plt.savefig(pic_IObytes,  format='png')
pic_IObytes.seek(0)
pic_hash = base64.b64encode(pic_IObytes.read())

The reason is both cStringIO and cStringIO.StringIO() are deprecated

I could not get answers above work, but this did:

    import io
    import base64
    s = io.BytesIO()
    plt.plot(list(range(100)))
    plt.savefig(s, format='png', bbox_inches="tight")
    plt.close()
    s = base64.b64encode(s.getvalue()).decode("utf-8").replace("\n", "")
    return '<img align="left" src="data:image/png;base64,%s">' % s