username        = 'your email'
passwd          = 'your pass'
doc_name        = 'PV data'

import sys
sys.path.append('../gdata')

import gdata.docs
import gdata.docs.service
import gdata.spreadsheet.service
import re, os


class GoogleSpreadsheet(object):
	'''Wrap up google gdata methods to access a Google spreadsheet'''
	
	def __init__(self, email, passwd): 
		# Connect to Google account
		self.gd_client = gdata.spreadsheet.service.SpreadsheetsService()
		self.gd_client.email = username
		self.gd_client.password = passwd
		self.gd_client.source = 'GoogleSpreadsheet wrapper class'
		self.gd_client.ProgrammaticLogin()


	def get_spreadsheet_id(self, spreadsheet_title):
		'''Get spreadsheet id by spreadsheet title'''
		doc_query = gdata.spreadsheet.service.DocumentQuery()
		doc_query['title'] = spreadsheet_title
		doc_query['title-exact'] = 'true'
		ss_feed = self.gd_client.GetSpreadsheetsFeed(query=doc_query)
		spreadsheet_id = ss_feed.entry[0].id.text.rsplit('/',1)[1]
		return spreadsheet_id
		

	def get_worksheet_id(self, spreadsheet_id, workbook_name):
		'''Get worksheet id by spreadsheet id and workbook name'''
		ws_feed = self.gd_client.GetWorksheetsFeed(spreadsheet_id)
		d = self.worksheet_dict(spreadsheet_id)
		try:
			id = d[workbook_name]
		except KeyError, e:
			print e
			id = None
		return id
				
		
	def worksheet_dict(self, spreadsheet_id):
		'''Create dictionary containing worsheet's ids with keys equal to 
		their names if spreadsheet_id is given.
		'''
		ws_feed = self.gd_client.GetWorksheetsFeed(spreadsheet_id)
		d = dict()
		for i, entry in enumerate(ws_feed.entry):
			d[entry.title.text] = entry.id.text.split('/')[-1] 
		return d
		

	def _get_num_cols(self, range):
		'''Compute the number of rows in a range'''
		# It's ugly, but I did not find a method in the API that does it
		pattern = re.compile('[\d]*$')
		first, second = range.split(':')
		m1 = re.search(pattern, first)
		m2 = re.search(pattern, second)
		ind1 = int(first[m1.start():])
		ind2 = int(second[m2.start():])
		num_cols = ind2 - ind1 + 1
		return num_cols
		

	def get_range(self, spreadsheet_id, worksheet_id, rng):
		'''Return cell range as a list of tuples, so that each element of 
		the tuple represents a row of data in the spreadsheet. The range 
		should be provided following standard R1C1 notation. This method 
		always returns a rectangular array. Empty cells are returned as 
		None.
		Parameters:
			spreadhseet_id -- spreadhseet id
			worksheet_id -- worksheet
			rng -- range of cells, e.g. 'A2:R23'
		'''
		# If range is given
		if rng is not None:
			cell_query = gdata.spreadsheet.service.CellQuery()
			cell_query['range'] = rng
			cell_query['return-empty'] = 'true' # oh, my!
		else:
			cell_query = None

		cell_feed = self.gd_client.GetCellsFeed(spreadsheet_id, worksheet_id, query=cell_query)
		entry = cell_feed.entry
		
		num_cols = self._get_num_cols(rng)
		num_rows = len(entry) / num_cols
		cells = []
		for ii in range(len(entry)):
			cells.append(entry[ii].content.text)		
		
		# Now reshape it to create num_rowsXnum_cols lists of tuples
		cells = zip(*[iter(cells)]*num_rows)
		return cells


	def get_cols(self, spreadsheet_id, worksheet_id, query=None):
		'''Reads entire workbook and returns dictionary, that contains
		column names as keys and list of column elements as dictionary
		values.
		'''
		if query is None:
			rows = self.gd_client.GetListFeed(spreadsheet_id, worksheet_id)
		else:
			rows = self.gd_client.GetListFeed(spreadsheet_id, worksheet_id, query)
		
		d = dict()
		# Build dictionary
		for row in rows.entry:
			for key in row.custom:
				if key in d.keys(): 
					d[key].append(row.custom[key].text)
				else:	
					d[key] = [row.custom[key].text]
				
		return d	
		
		
	def get_list_query(self, query_str):
		'''Retun an instance of ListQuery suitable to pass to the get_cols
		method. You may set query parameters by setting up query keys. 
		Query keys:
			sq: for general query such as 'name=john&last=smith'
			orderby: for example: 'column:first'
			reverse: values are 'true' and 'false', note these are string.
		'''
		list_query = gdata.spreadsheet.service.ListQuery()
		
		return list_query	
	
if __name__ == '__main__':
	# Let's roll

	gs = GoogleSpreadsheet(username, passwd)
	sid = gs.get_spreadsheet_id(doc_name)
	print sid
	wid = gs.get_worksheet_id(sid, 'Sheet1')
	print wid
	cls = gs.get_range(sid, wid, 'A1:C5')
	print cls
	d = gs.get_cols(sid, wid)	
	print d