Expected b'battery_v'but got b'battery:...' error communicating with Pisgar3

from pisugar import*
import datetime
import csv
import time


conn, event_conn = connect_tcp('raspberrypi.local')
s = PiSugarServer(conn, event_conn)

#s.register_single_tap_handler(lambda:print('single'))) What was mentioned in the github of pisgar? I don't understand this sentence.
#s.register_double_tap_handler(lambda:print('double'))) I don't understand this sentence.


#csv Configuration
path=open(r"data/log.csv", 'a', newline=')
f=csv.writer(path)
writer=f


# acquisition time interval
inter=5# Set the interval time in seconds

list = ' '

def writeecsv():

# pisugar_API
    battery=s.get_battery_power_plugged()#Power Supply Method
    battery=s.get_battery_level()#battery remaining
    v=s.get_battery_voltage()#

# time setting
    dt_nowrow=datetime.datetime.now()
    dt_now = dt_nowrow.strftime ('%Y year %m month %d day %H:%M:%S')
    list = [dt_now, battery plug, battery level, v]
    writer.writerow (list)
    print(list)


#csv, writing
writer.writerow ('Time Stamp', 'Power Supply', 'Battery Remaining', 'Voltage')
while True:
    shutdownlevel=s.get_battery_level()# shutdown factor

    writeecsv()
    time.sleep(inter)
    
    if (shutdownlevel<10):
        break