python – 实时DataFrame图

我有一个pandas DataFrame,它在while循环中更新,我想实时绘制这个,但不幸的是我没有得到如何做到这一点.
一个samplae代码可能是：

import numpy as np
from matplotlib import pyplot as plt
from matplotlib import animation
import time as tm
from datetime import datetime, date, time
import pandas as pd

columns = ["A1", "A2", "A3", "A4","A5", "B1", "B2", "B3", "B4", "B5", "prex"]
df = pd.DataFrame()
"""plt.ion()"""
plt.figure()
while not True:

    Now = datetime.Now()
    adata = 5 * np.random.randn(1,10) + 25.
    prex = 1e-10* np.random.randn(1,1) + 1e-10
    outcomes = np.append(adata, prex)
    ind = [Now]
    idf = pd.DataFrame(np.array([outcomes]), index = ind, columns = columns)
    df = df.append(idf)
    ax = df.plot(secondary_y=['prex'])

    plt.show()
    time.sleep(0.5)

但如果我取消注释“”“plt.ion()”“”我会打开许多​​不同的窗口.否则我必须关闭窗口才能获得更新的图.
有什么建议？

解决方法:

您可以指定要使用的plot轴,而不是每次调用时创建不同的轴.要在交互模式下重绘绘图,可以使用draw而不是show.

from matplotlib import animation
import time as tm
from datetime import datetime, date, time
import pandas as pd

columns = ["A1", "A2", "A3", "A4","A5", "B1", "B2", "B3", "B4", "B5", "prex"]
df = pd.DataFrame()
plt.ion()
fig = plt.figure()
ax = fig.add_subplot(111) # Create an axes. 
while True:

    Now = datetime.Now()
    adata = 5 * np.random.randn(1,10) + 25.
    prex = 1e-10* np.random.randn(1,1) + 1e-10
    outcomes = np.append(adata, prex)
    ind = [Now]
    idf = pd.DataFrame(np.array([outcomes]), index = ind, columns = columns)
    df = df.append(idf)
    df.plot(secondary_y=['prex'], ax = ax) # Pass the axes to plot. 

    plt.draw() # Draw instead of show to update the plot in ion mode. 
    tm.sleep(0.5)