text: #!/usr/bin/python
  
  # Google Spreadsheet DHT Sensor Data-logging Example
  
  # Depends on the 'gspread' and 'oauth2client' package being installed.  If you
  # have pip installed execute:
  #   sudo pip install gspread oauth2client
  
  # Also it's _very important_ on the Raspberry Pi to install the python-openssl
  # package because the version of Python is a bit old and can fail with Google's
  # new OAuth2 based authentication.  Run the following command to install the
  # the package:
  #   sudo apt-get update
  #   sudo apt-get install python-openssl
  
  # Copyright (c) 2014 Adafruit Industries
  # Author: Tony DiCola
  
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  
  # The above copyright notice and this permission notice shall be included in all
  # copies or substantial portions of the Software.
  
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  # SOFTWARE.
  import json
  import sys
  import time
  import datetime
  
  import Adafruit_DHT
  import gspread
  from oauth2client.service_account import ServiceAccountCredentials
  
  # Type of sensor, can be Adafruit_DHT.DHT11, Adafruit_DHT.DHT22, or Adafruit_DHT.AM2302.
  DHT_TYPE = Adafruit_DHT.DHT22
  
  # Example of sensor connected to Raspberry Pi pin 23
  DHT_PIN = 23
  # Example of sensor connected to Beaglebone Black pin P8_11
  # DHT_PIN  = 'P8_11'
  
  # Google Docs OAuth credential JSON file.  Note that the process for authenticating
  # with Google docs has changed as of ~April 2015.  You _must_ use OAuth2 to log
  # in and authenticate with the gspread library.  Unfortunately this process is much
  # more complicated than the old process.  You _must_ carefully follow the steps on
  # this page to create a new OAuth service in your Google developer console:
  #   http://gspread.readthedocs.org/en/latest/oauth2.html
  #
  # Once you've followed the steps above you should have downloaded a .json file with
  # your OAuth2 credentials.  This file has a name like SpreadsheetData-<gibberish>.json.
  # Place that file in the same directory as this python script.
  #
  # Now one last _very important_ step before updating the spreadsheet will work.
  # Go to your spreadsheet in Google Spreadsheet and share it to the email address
  # inside the 'client_email' setting in the SpreadsheetData-*.json file.  For example
  # if the client_email setting inside the .json file has an email address like:
  #   149345334675-md0qff5f0kib41meu20f7d1habos3qcu@developer.gserviceaccount.com
  # Then use the File -> Share... command in the spreadsheet to share it with read
  # and write acess to the email address above.  If you don't do this step then the
  # updates to the sheet will fail!
  GDOCS_OAUTH_JSON = 'your SpreadsheetData-*.json file name'
  
  # Google Docs spreadsheet name.
  GDOCS_SPREADSHEET_NAME = 'your google docs spreadsheet name'
  
  # How long to wait (in seconds) between measurements.
  FREQUENCY_SECONDS = 30
  
  
  def login_open_sheet(oauth_key_file, spreadsheet):
      """Connect to Google Docs spreadsheet and return the first worksheet."""
      try:
          scope = ['https://spreadsheets.google.com/feeds']
          credentials = ServiceAccountCredentials.from_json_keyfile_name(oauth_key_file, scope)
          gc = gspread.authorize(credentials)
          worksheet = gc.open(spreadsheet).sheet1
          return worksheet
      except Exception as ex:
          print(
              'Unable to login and get spreadsheet.  Check OAuth credentials, spreadsheet name, and make sure spreadsheet is shared to the client_email address in the OAuth .json file!')
          print('Google sheet login failed with error:', ex)
          sys.exit(1)
  
  
  print('Logging sensor measurements to {0} every {1} seconds.'.format(GDOCS_SPREADSHEET_NAME, FREQUENCY_SECONDS))
  print('Press Ctrl-C to quit.')
  worksheet = None
  while True:
      # Login if necessary.
      if worksheet is None:
          worksheet = login_open_sheet(GDOCS_OAUTH_JSON, GDOCS_SPREADSHEET_NAME)
  
      # Attempt to get sensor reading.
      humidity, temp = Adafruit_DHT.read(DHT_TYPE, DHT_PIN)
  
      # Skip to the next reading if a valid measurement couldn't be taken.
      # This might happen if the CPU is under a lot of load and the sensor
      # can't be reliably read (timing is critical to read the sensor).
      if humidity is None or temp is None:
          time.sleep(2)
          continue
  
      print('Temperature: {0:0.1f} C'.format(temp))
      print('Humidity:    {0:0.1f} %'.format(humidity))
  
      # Append the data in the spreadsheet, including a timestamp
      try:
          worksheet.append_row((datetime.datetime.now(), temp, humidity))
      except:
          # Error appending data, most likely because credentials are stale.
          # Null out the worksheet so a login is performed at the top of the loop.
          print('Append error, logging in again')
          worksheet = None
          time.sleep(FREQUENCY_SECONDS)
          continue
  
      # Wait 30 seconds before continuing
      print('Wrote a row to {0}'.format(GDOCS_SPREADSHEET_NAME))
      time.sleep(FREQUENCY_SECONDS)
  