Question

我正在使用matplotlib.pyplot实时绘制一些值。我将值放在双端队列中，然后将其传递给绘图函数。我想将最大大小设置为7;因此，在插入超过第7个索引的所有内容之后，将弹出第一项，但它似乎不起作用；

python

import matplotlib.pyplot as plt
import time
from collections import deque as dq

# the auguments in this function are inter process queues which contain the data produced by another process 
# the data is in a json format and looks like the following;
'''
{'memory_state': 22.7, 'host_ip': '192.168.204.130', 'net_down': 1958707880, 'time_stamp': '12:27:42', 'cpu_utilization': 0.0, 'net_up': 5998207783, 'sec': 42, 'dropped_packets': 0}
'''

def  do_plot(sys_monitor_queue):

    print('do_plot loop running')
    list_size = 6

    monitor_x_values,monitor_net_down = dq([],maxlen=list_size),dq([],maxlen=list_size)

    plt.rcParams['animation.html'] ='jshtml'

    fig = plt.figure(figsize=(12,8))
    fig.show()
    system_monitor_plot = fig.add_subplot(111)
    while True:

        plt.title('Network Inbound Traffic')    
        plt.xlabel('Time/second', fontsize=14)
        plt.ylabel('Packets / mbps',fontsize=14)
        plt.tick_params(axis ='both', labelsize=14)

        plt.xticks(rotation = 90)
        if not sys_monitor_queue.empty():
            try:
                rv_monitor = sys_monitor_queue.get()
                monitor_net_down.append(int(rv_monitor["net_down"])/1000000)
                monitor_x_values.append(rv_monitor['time_stamp'])
                system_monitor_plot.plot(monitor_x_values, monitor_net_down, linewidth=1)
                fig.canvas.draw()

            except Exception as exception:
                print("do_plot_exception :", exception)

                continue        
        else: 
            time.sleep(1)

该绘图实际上是可以工作的，只是它被压缩了，因为双端队列未按预期弹出旧项目

每次插入超过最大长度后，collections.deque是否实际上会弹出第一个元素？

0 个答案: