How to properly assign serial output to value with ser.readlines for further usage?

I am newbie and wrote a script, which initiates com开发者_运维百科munication ("/?!") to an energy meter through serial USBport and reads out the incoming energy log. It extracts different values from the output and writes those into a local sqlite-db. It is suppose to run as a cronjob every 15min. A php-website will visualize the sqlite-stored energy readings as a graph btw.

At the moment I don't have access to the meter, it is very remote and cold there, so I need to have it right before I go there.

If I am trying to execute script it raises Error: ser.readlines(eol='!') = z

SyntaxError: can't assign to function call

is my reading with ser.readlines of the serial output and assigning to value z wrong?

the script (regex & inserting into DB) works if I open a logfile with similiar values in it: e.g. with open ("log") as z:..

#!/usr/bin/env python
import serial  
import time  
import re  
import sqlite3  

ser = serial.Serial('/dev/ttyUSB0', 300, bytesize=serial.SEVENBITS, parity=serial.PARITY_EVEN, stopbits=serial.STOPBITS_ONE, timeout=2)
ser.open()

ser.write("/?!")  
time.sleep(0.001)  
ser.write("\r")    

connection = sqlite3.connect('/path/to/dbname.db')  
cursor = connection.cursor()  
extrakt = []

ser.readlines(eol='!') = z   
for line in z:  
            match = re.search(r'(0\.0\.0|1\.6\.1|1\.8\.1)\(([0-9\.]+)', line)  
            if match: 
                    version,value = match.groups() 
                    extrakt.append(value)

cursor.execute('INSERT INTO energielog (sernr, peak, kwh) values (?, ?, ?)', extrakt)
connection.commit()

ser.close()  
cursor.close()  
connection.close()

I think instead of

ser.readlines(eol='!') = z
for line in z:    

you probably want

for line in ser.readlines(eol='!'):