python cgi script to generate temperature data in JSON format

raspiweb.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import cgi
import json
import re
import os
import hashlib
import base64
import datetime

from pbkdf2 import safe_str_cmp, pbkdf2_hex


# get cgi object
form = cgi.FieldStorage()

# example values, change when going online
salt     = "a683c64de226677703f56e6b6ead94bbc3690ec5293c3de3ffdc932dc54aa44b"
password = "3404ca4e934bee674610d350a736bcd8ef02db768765a19e45e53f2a5c8ce982"
userpwd  = ""

# get pwd, salt it, hash it
if (form.getvalue('pwd')):
        userpwd = pbkdf2_hex(base64.b64decode(form.getvalue('pwd')), salt, 1000, 32, hashlib.sha256)

regstring = '\d\d\d\d,\d\d\,\d\d'

if (form.getvalue('period')):
        period = form.getvalue('period')
        if (period == "0"):
                regstring = datetime.datetime.now().strftime('%Y,%m,%d')
        if (period == "1"):
                regstring = datetime.datetime.now().strftime('%Y,%m,') + '\d\d'

# pwd correct
if (safe_str_cmp(userpwd, password)):

        # open temp log txt file & find requested temp data
        f = open("/home/pi/projects/temp.log", "rb")

        if (period == "3"):
                f.seek(-48, 2)

        # find date & temp strings
        datetemps = re.findall(r'' + regstring + '\s+\d\d\,\d\d\,\d\d\s+\d\d\.\d\d\d\s+\d\d\.\d\d\d', f.read())

        f.close()

        # generate temp strings
        dates = [date[:20] for date in datetemps]
        room = [float(temp[25:30]) for temp in datetemps]
        cpu = [float(temp[-6:-1]) for temp in datetemps]

        # put date & temp strings into json object
        data = json.dumps({'pwdvalid': 1,'time': dates, 'room': room, 'cpu': cpu}, separators=(',',':'))

# pwd incorrect
else:
        
        now = datetime.datetime.now().strftime('%d.%m.%Y %H:%M:%S')
        f = open("../raspiweb/access.log", "ab")
        f.write(now + " : " + cgi.escape(os.environ["REMOTE_ADDR"]) + " : incorrect password\n")
        f.close()
        data = json.dumps({'pwdvalid': 0}, separators=(',',':'))


# http response with the json object
print("Content-type: text/html\n")
print(data)