jupyter_client execute方法返回对象而不是图像

Question

我正在尝试使用jupyter_client执行python代码来执行一个方法，并将结果期望为图像（base64），而不是我得到了Object。

from jupyter_client import KernelManager
import time
try:
    from queue import Empty  # Py 3                                                             
except ImportError:
    from Queue import Empty  # Py 2                                                             

#km = KernelManager(kernel_name='ir')
km = KernelManager(kernel_name='python3')
km.start_kernel()
print (km.is_alive())
try:
    c = km.client()
    msg_id=c.execute('from matplotlib import pyplot as plt;plt.plot([1,2,3],[4,5,1]);plt.show()')
    #msg_id=c.execute('x <- c(21, 62, 10, 53);labels <- c("London", "New York", "Singapore", "Mumbai");pie(x,labels)')
    state='busy'
    data={}
    while state!='idle' and c.is_alive():
        try:
            msg=c.get_iopub_msg(timeout=100)
            if not 'content' in msg: continue
            content = msg['content']
            if 'data' in content:
                data=content['data']
            if 'execution_state' in content:
                state=content['execution_state']
        except Empty:
            pass
#    print(msg) 
    print (data)
except KeyboardInterrupt:
    pass
finally:
    km.shutdown_kernel()
    print (km.is_alive())

我期待图像但是得到'