我是python的新手。我正在编写一个数据记录程序，想要打开一个串口，然后从中读取。
我的问题是在我的main（）中调用它：
# Handle serial
ser = serial.Serial(strPort, 9600)
不允许我在其他函数中调用ser句柄上的方法。我应该上课还是最好的方法？
以下是错误消息：
line 164, in updateData
line = ser.readline().rstrip()
NameError: name 'ser' is not defined
以下是代码：
# Uncomment the next two lines if you want to save the animation
import matplotlib
# matplotlib.use("Agg")
import sys
import serial
import argparse
import csv
import numpy
from matplotlib.pylab import *
from mpl_toolkits.axes_grid1 import host_subplot
import matplotlib.animation as animation
'''
ax03.legend([p031,p032], [p031.get_label(),p032.get_label()])
'''
def main():
# Sent for figure
font = {'size': 9}
matplotlib.rc('font', **font)
# Setup figure and subplots
f0 = figure(num=0, figsize=(12, 10)) # , dpi = 100)
f0.suptitle("Sensor Data", fontsize=12)
ax01 = subplot2grid((3, 2), (1, 0))
#ax02 = subplot2grid((4, 2), (1, 1))
ax02 = ax01.twinx()
ax03 = subplot2grid((3, 2), (0, 0), colspan=2, rowspan=1)
ax04 = subplot2grid((3, 2), (1, 1))
ax05 = subplot2grid((3, 2), (2, 0))
ax06 = subplot2grid((3, 2), (2, 1))
subplots_adjust(left=None, bottom=None, right=None,
top=None, wspace=0.3, hspace=0.3)
# Set titles of subplots
ax01.set_title('Heart Rate Quality and Sample Frequency')
ax03.set_title('Heart Rate')
ax04.set_title('Step Rate')
ax05.set_title('Perfusion Index')
ax06.set_title('Raw PPG')
# set y-limits
ax01.set_ylim(-1, 5)
ax02.set_ylim(100, 500)
ax03.set_ylim(30, 140)
ax04.set_ylim(-50, 250)
ax05.set_ylim(0, 500)
ax06.set_ylim(0, 50000)
# sex x-limits
ax01.set_xlim(0, 50.0)
# ax02.set_xlim(0,50.0)
ax03.set_xlim(0, 50.0)
ax04.set_xlim(0, 50.0)
ax05.set_xlim(0, 50.0)
ax06.set_xlim(0, 50.0)
# Turn on grids
ax01.grid(True)
# ax02.grid(True)
ax03.grid(True)
ax04.grid(True)
ax05.grid(True)
ax06.grid(True)
# set label names
ax01.set_xlabel("t[s]")
ax01.set_ylabel("HRQ")
ax02.set_xlabel("t[s]")
ax02.set_ylabel("samples[Hz]")
ax03.set_xlabel("t[s]")
ax03.set_ylabel("bpm")
ax04.set_xlabel("t[s]")
ax04.set_ylabel("Steps/min")
ax05.set_xlabel("t[s]")
ax05.set_ylabel("AC/DC ratio")
ax06.set_xlabel("t[s]")
ax06.set_ylabel("raw PS sample")
# Data Placeholders
t = zeros(0)
hr = zeros(0)
HRQ = zeros(0)
Fs = zeros(0)
stepRate = zeros(0)
ADCGain = zeros(0)
pI = zeros(0)
rawPPG = zeros(0)
ser = zeros(0)
# set plots
p011, = ax01.plot(t, HRQ, 'c-', label="HRQ", linewidth=2)
p021, = ax02.plot(t, ADCGain, 'r-', label="Sample Frequency", linewidth=2)
p031, = ax03.plot(t, hr, 'b-', label="Heart Rate", linewidth=2)
p041, = ax04.plot(t, stepRate, 'b-', label="Step Rate", linewidth=2)
p051, = ax05.plot(t, pI, 'y-', label="Perfusion Index", linewidth=2)
p061, = ax06.plot(t, rawPPG, 'g-', label="Raw PPG", linewidth=2)
# set lagends
ax01.legend([p011, p021], [p011.get_label(), p021.get_label()], loc=2)
#ax02.legend([p021], [p021.get_label()])
ax03.legend([p031], [p031.get_label()], loc=2)
ax04.legend([p041], [p041.get_label()], loc=2)
ax05.legend([p051], [p051.get_label()], loc=2)
ax06.legend([p061], [p061.get_label()], loc=2)
# Data Update
xmin = 0.0
xmax = 50.0
x = 0.0
# create parser
parser = argparse.ArgumentParser(description="LDR serial")
# add expected arguments
parser.add_argument('--port', dest='port', required=True)
# parse args
args = parser.parse_args()
#strPort = '/dev/tty.usbserial-A7006Yqh'
strPort = args.port
print('reading from serial port %s...' % strPort)
# Handle serial
ser = serial.Serial(strPort, 9600)
print('plotting data...')
# Logfile writer
# open('test.csv','w') as csvfile
#logwriter = csv.writer(csvfile, delimiter=' ', quotechar='|', quoting=csv.QUOTE_MINIMAL)
# interval: draw new frame every 'interval' ms
# frames: number of frames to draw
simulation = animation.FuncAnimation(
f0, updateData, blit=False, frames=1000, interval=100, repeat=True)
# Uncomment the next line if you want to save the animation
# simulation.save(filename='sim.mp4',fps=1,dpi=300)
plt.show()
def updateData(self):
global x
global t
global ser
global hr
global HRQ
global Fs
global ADCGain
global stepRate
global pI
global rawPPG
try:
line = ser.readline().rstrip()
data = [float(val) for val in line.split()]
# print data
print(data)
if(len(data) == 9):
# log data
for i in range(len(data)):
out_string = ""
out_string += str(data[i])
# logwriter.writerow(out_string)
# update variables
tmpT = data[0]
tmpFs = data[1]
tmpStepRate = data[2]
tmpHr = data[3]
tmpPI = data[4]
tmpHRQ = data[5]
tmpRawPPG = data[6]
except KeyboardInterrupt:
print('exiting')
hr = append(hr, tmpHr)
HRQ = append(HRQ, tmpHRQ)
Fs = append(Fs, tmpFs)
stepRate = append(stepRate, tmpStepRate)
pI = append(pI, tmpPI)
rawPPG = append(rawPPG, tmpRawPPG)
t = append(t, x)
x += 1
p011.set_data(t, HRQ)
p021.set_data(t, Fs)
p031.set_data(t, hr)
p041.set_data(t, stepRate)
p051.set_data(t, pI)
p061.set_data(t, rawPPG)
if x >= xmax - 10.00:
p011.axes.set_xlim(x - xmax + 10.0, x + 10.0)
p021.axes.set_xlim(x - xmax + 10.0, x + 10.0)
p031.axes.set_xlim(x - xmax + 10.0, x + 10.0)
p041.axes.set_xlim(x - xmax + 10.0, x + 10.0)
p051.axes.set_xlim(x - xmax + 10.0, x + 10.0)
p061.axes.set_xlim(x - xmax + 10.0, x + 10.0)
return p011, p021, p031, p041, p051, p061
# Call main
if __name__ == '__main__':
main()