First you'll need to generate OAuth2 credentials:
http://gspread.readthedocs.io/en/latest/oauth2.html
You'll need to create a new authorization object in your Python using the OAuth2 credentials:
gc = gspread.authorize(credentials)
Then you need to create a connection to the worksheet:
# If you want to be specific, use a key (which can be extracted from
# the spreadsheet's url)
yoursheet = gc.open_by_key('0BmgG6nO_6dprdS1MN3d3MkdPa142WFRrdnRRUWl1UFE')
# Or, if you feel really lazy to extract that key, paste the entire url
yoursheet = gc.open_by_url('https://docs.google.com/spreadsheet/ccc?key=0Bm...FE&hl')
Then you can grab the cell you want
val = yoursheet.acell('B1').value
All code was pulled from the gspread Github basic usage with minor tweaks https://github.com/burnash/gspread
Cheers!