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Je voudrais faire un graphique en temps réel en pyqt en utilisant les données d'une table mysql, mais je ne sais pas comment. La table sera mise à jour toutes les secondes et aura des pourcentages de CPU (par exemple 2.5, 3.5, 4.5). Je ne suis pas sûr de savoir comment créer un graphique en temps réel avec les données de mysql.Graphiques avec Pyqt et en utilisant les données de mysql
J'ai créé un graphique matplotlib simple ci-dessous. J'ai essayé d'incorporer les données mysql mais je suis incapable de répondre aux besoins de ce graphique en temps réel.
import sys
from PyQt4 import QtGui
from matplotlib.figure import Figure
from matplotlib.backends.backend_qt4agg \
import FigureCanvasQTAgg as FigureCanvas
import psutil as p
# Total number of iterations
MAXITERS = 2000
class CPUMonitor(FigureCanvas):
"""Matplotlib Figure widget to display CPU utilization"""
def __init__(self):
# save the current CPU info (used by updating algorithm)
self.before = self.prepare_cpu_usage()
# first image setup
self.fig = Figure()
self.ax = self.fig.add_subplot(111)
# initialization of the canvas
FigureCanvas.__init__(self, self.fig)
# set specific limits for X and Y axes
self.ax.set_xlim(0, 2000)
self.ax.set_ylim(0, 100)
# and disable figure-wide autoscale
self.ax.set_autoscale_on(False)
# generates first "empty" plots
self.user, self.nice, self.sys, self.idle =[], [], [], []
self.l_user, = self.ax.plot([],self.user, label='User %')
self.l_nice, = self.ax.plot([],self.nice, label='Nice %')
self.l_sys, = self.ax.plot([],self.sys, label='Sys %')
self.l_idle, = self.ax.plot([],self.idle, label='Idle %')
# add legend to plot
self.ax.legend()
# force a redraw of the Figure
self.fig.canvas.draw()
# initialize the iteration counter
self.cnt = 0
# call the update method (to speed-up visualization)
self.timerEvent(None)
# start timer, trigger event every 1000 millisecs (=1sec)
self.timer = self.startTimer(1000)
def prepare_cpu_usage(self):
"""helper function to return CPU usage info"""
# get the CPU times using psutil module
t = p.cpu_times()
# return only the values we're interested in
if hasattr(t, 'nice'):
return [t.user, t.nice, t.system, t.idle]
else:
# special case focr Windows, without 'nice' value
return [t.user, 0, t.system, t.idle]
def get_cpu_usage(self):
"""Compute CPU usage comparing previous and current measurements"""
# take the current CPU usage information
now = self.prepare_cpu_usage()
# compute delta between current and previous measurements
delta = [now[i]-self.before[i] for i in range(len(now))]
# compute the total (needed for percentages calculation)
total = sum(delta)
# save the current measurement to before object
self.before = now
# return the percentage of CPU usage for our 4 categories
return [(100.0*dt)/total for dt in delta]
def timerEvent(self, evt):
# get the cpu percentage usage
result = self.get_cpu_usage()
# append new data to the datasets
self.user.append(result[0])
self.nice.append(result[1])
self.sys.append(result[2])
self.idle.append(result[3])
# update lines data using the lists with new data
self.l_user.set_data(range(len(self.user)), self.user)
self.l_nice.set_data(range(len(self.nice)), self.nice)
self.l_sys.set_data(range(len(self.sys)), self.sys)
self.l_idle.set_data(range(len(self.idle)), self.idle)
# force a redraw of the Figure
self.fig.canvas.draw()
if self.cnt == MAXITERS:
# stop the timer
self.killTimer(self.timer)
else:
#else, we increment the counter
self.cnt += 1
# create the GUI application
widget = CPUMonitor()
widget.setWindowTitle("30 Seconds of CPU Usage Updated in RealTime")
widget.show()
sys.exit(app.exec_())