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#!/usr/bin/python
#
# Copyright Google 2007-2008, all rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import StringIO
import gdata
import gdata.service
import gdata.spreadsheet
import gdata.spreadsheet.service
import gdata.docs
import gdata.docs.service
"""Make the Google Documents API feel more like using a database.
This module contains a client and other classes which make working with the
Google Documents List Data API and the Google Spreadsheets Data API look a
bit more like working with a heirarchical database. Using the DatabaseClient,
you can create or find spreadsheets and use them like a database, with
worksheets representing tables and rows representing records.
Example Usage:
# Create a new database, a new table, and add records.
client = gdata.spreadsheet.text_db.DatabaseClient(username='jo@example.com',
password='12345')
database = client.CreateDatabase('My Text Database')
table = database.CreateTable('addresses', ['name','email',
'phonenumber', 'mailingaddress'])
record = table.AddRecord({'name':'Bob', 'email':'bob@example.com',
'phonenumber':'555-555-1234', 'mailingaddress':'900 Imaginary St.'})
# Edit a record
record.content['email'] = 'bob2@example.com'
record.Push()
# Delete a table
table.Delete
Warnings:
Care should be exercised when using this module on spreadsheets
which contain formulas. This module treats all rows as containing text and
updating a row will overwrite any formula with the output of the formula.
The intended use case is to allow easy storage of text data in a spreadsheet.
Error: Domain specific extension of Exception.
BadCredentials: Error raised is username or password was incorrect.
CaptchaRequired: Raised if a login attempt failed and a CAPTCHA challenge
was issued.
DatabaseClient: Communicates with Google Docs APIs servers.
Database: Represents a spreadsheet and interacts with tables.
Table: Represents a worksheet and interacts with records.
RecordResultSet: A list of records in a table.
Record: Represents a row in a worksheet allows manipulation of text data.
"""
__author__ = 'api.jscudder (Jeffrey Scudder)'
class Error(Exception):
pass
class BadCredentials(Error):
pass
class CaptchaRequired(Error):
pass
class DatabaseClient(object):
"""Allows creation and finding of Google Spreadsheets databases.
The DatabaseClient simplifies the process of creating and finding Google
Spreadsheets and will talk to both the Google Spreadsheets API and the
Google Documents List API.
"""
def __init__(self, username=None, password=None):
"""Constructor for a Database Client.
If the username and password are present, the constructor will contact
the Google servers to authenticate.
Args:
username: str (optional) Example: jo@example.com
password: str (optional)
"""
self.__docs_client = gdata.docs.service.DocsService()
self.__spreadsheets_client = (
gdata.spreadsheet.service.SpreadsheetsService())
self.SetCredentials(username, password)
def SetCredentials(self, username, password):
"""Attempts to log in to Google APIs using the provided credentials.
If the username or password are None, the client will not request auth
tokens.
Args:
username: str (optional) Example: jo@example.com
password: str (optional)
"""
self.__docs_client.email = username
self.__docs_client.password = password
self.__spreadsheets_client.email = username
self.__spreadsheets_client.password = password
if username and password:
try:
self.__docs_client.ProgrammaticLogin()
self.__spreadsheets_client.ProgrammaticLogin()
except gdata.service.CaptchaRequired:
raise CaptchaRequired('Please visit https://www.google.com/accounts/'
'DisplayUnlockCaptcha to unlock your account.')
except gdata.service.BadAuthentication:
raise BadCredentials('Username or password incorrect.')
def CreateDatabase(self, name):
"""Creates a new Google Spreadsheet with the desired name.
Args:
name: str The title for the spreadsheet.
Returns:
A Database instance representing the new spreadsheet.
"""
# Create a Google Spreadsheet to form the foundation of this database.
# Spreadsheet is created by uploading a file to the Google Documents
# List API.
virtual_csv_file = StringIO.StringIO(',,,')
virtual_media_source = gdata.MediaSource(file_handle=virtual_csv_file, content_type='text/csv', content_length=3)
db_entry = self.__docs_client.UploadSpreadsheet(virtual_media_source, name)
return Database(spreadsheet_entry=db_entry, database_client=self)
def GetDatabases(self, spreadsheet_key=None, name=None):
"""Finds spreadsheets which have the unique key or title.
If querying on the spreadsheet_key there will be at most one result, but
searching by name could yield multiple results.
Args:
spreadsheet_key: str The unique key for the spreadsheet, this
usually in the the form 'pk23...We' or 'o23...423.12,,,3'.
name: str The title of the spreadsheets.
Returns:
A list of Database objects representing the desired spreadsheets.
"""
if spreadsheet_key:
db_entry = self.__docs_client.GetDocumentListEntry(
r'/feeds/documents/private/full/spreadsheet%3A' + spreadsheet_key)
return [Database(spreadsheet_entry=db_entry, database_client=self)]
else:
title_query = gdata.docs.service.DocumentQuery()
title_query['title'] = name
db_feed = self.__docs_client.QueryDocumentListFeed(title_query.ToUri())
matching_databases = []
for entry in db_feed.entry:
matching_databases.append(Database(spreadsheet_entry=entry,
database_client=self))
return matching_databases
def _GetDocsClient(self):
return self.__docs_client
def _GetSpreadsheetsClient(self):
return self.__spreadsheets_client
class Database(object):
"""Provides interface to find and create tables.
The database represents a Google Spreadsheet.
"""
def __init__(self, spreadsheet_entry=None, database_client=None):
"""Constructor for a database object.
Args:
spreadsheet_entry: gdata.docs.DocumentListEntry The
Atom entry which represents the Google Spreadsheet. The
spreadsheet's key is extracted from the entry and stored as a
member.
database_client: DatabaseClient A client which can talk to the
Google Spreadsheets servers to perform operations on worksheets
within this spreadsheet.
"""
self.entry = spreadsheet_entry
if self.entry:
id_parts = spreadsheet_entry.id.text.split('/')
self.spreadsheet_key = id_parts[-1].replace('spreadsheet%3A', '')
self.client = database_client
def CreateTable(self, name, fields=None):
"""Add a new worksheet to this spreadsheet and fill in column names.
Args:
name: str The title of the new worksheet.
fields: list of strings The column names which are placed in the
first row of this worksheet. These names are converted into XML
tags by the server. To avoid changes during the translation
process I recommend using all lowercase alphabetic names. For
example ['somelongname', 'theothername']
Returns:
Table representing the newly created worksheet.
"""
worksheet = self.client._GetSpreadsheetsClient().AddWorksheet(title=name,
row_count=1, col_count=len(fields), key=self.spreadsheet_key)
return Table(name=name, worksheet_entry=worksheet,
database_client=self.client,
spreadsheet_key=self.spreadsheet_key, fields=fields)
def GetTables(self, worksheet_id=None, name=None):
"""Searches for a worksheet with the specified ID or name.
The list of results should have one table at most, or no results
if the id or name were not found.
Args:
worksheet_id: str The ID of the worksheet, example: 'od6'
name: str The title of the worksheet.
Returns:
A list of length 0 or 1 containing the desired Table. A list is returned
to make this method feel like GetDatabases and GetRecords.
"""
if worksheet_id:
worksheet_entry = self.client._GetSpreadsheetsClient().GetWorksheetsFeed(
self.spreadsheet_key, wksht_id=worksheet_id)
return [Table(name=worksheet_entry.title.text,
worksheet_entry=worksheet_entry, database_client=self.client,
spreadsheet_key=self.spreadsheet_key)]
else:
matching_tables = []
query = None
if name:
query = gdata.spreadsheet.service.DocumentQuery()
query.title = name
worksheet_feed = self.client._GetSpreadsheetsClient().GetWorksheetsFeed(
self.spreadsheet_key, query=query)
for entry in worksheet_feed.entry:
matching_tables.append(Table(name=entry.title.text,
worksheet_entry=entry, database_client=self.client,
spreadsheet_key=self.spreadsheet_key))
return matching_tables
def Delete(self):
"""Deletes the entire database spreadsheet from Google Spreadsheets."""
entry = self.client._GetDocsClient().Get(
r'http://docs.google.com/feeds/documents/private/full/spreadsheet%3A' +
self.spreadsheet_key)
self.client._GetDocsClient().Delete(entry.GetEditLink().href)
class Table(object):
def __init__(self, name=None, worksheet_entry=None, database_client=None,
spreadsheet_key=None, fields=None):
self.name = name
self.entry = worksheet_entry
id_parts = worksheet_entry.id.text.split('/')
self.worksheet_id = id_parts[-1]
self.spreadsheet_key = spreadsheet_key
self.client = database_client
self.fields = fields or []
if fields:
self.SetFields(fields)
def LookupFields(self):
"""Queries to find the column names in the first row of the worksheet.
Useful when you have retrieved the table from the server and you don't
know the column names.
"""
if self.entry:
first_row_contents = []
query = gdata.spreadsheet.service.CellQuery()
query.max_row = '1'
query.min_row = '1'
feed = self.client._GetSpreadsheetsClient().GetCellsFeed(
self.spreadsheet_key, wksht_id=self.worksheet_id, query=query)
for entry in feed.entry:
first_row_contents.append(entry.content.text)
# Get the next set of cells if needed.
next_link = feed.GetNextLink()
while next_link:
feed = self.client._GetSpreadsheetsClient().Get(next_link.href,
converter=gdata.spreadsheet.SpreadsheetsCellsFeedFromString)
for entry in feed.entry:
first_row_contents.append(entry.content.text)
next_link = feed.GetNextLink()
# Convert the contents of the cells to valid headers.
self.fields = ConvertStringsToColumnHeaders(first_row_contents)
def SetFields(self, fields):
"""Changes the contents of the cells in the first row of this worksheet.
Args:
fields: list of strings The names in the list comprise the
first row of the worksheet. These names are converted into XML
tags by the server. To avoid changes during the translation
process I recommend using all lowercase alphabetic names. For
example ['somelongname', 'theothername']
"""
# TODO: If the table already had fields, we might want to clear out the,
# current column headers.
self.fields = fields
i = 0
for column_name in fields:
i = i + 1
# TODO: speed this up by using a batch request to update cells.
self.client._GetSpreadsheetsClient().UpdateCell(1, i, column_name,
self.spreadsheet_key, self.worksheet_id)
def Delete(self):
"""Deletes this worksheet from the spreadsheet."""
worksheet = self.client._GetSpreadsheetsClient().GetWorksheetsFeed(
self.spreadsheet_key, wksht_id=self.worksheet_id)
self.client._GetSpreadsheetsClient().DeleteWorksheet(
worksheet_entry=worksheet)
def AddRecord(self, data):
"""Adds a new row to this worksheet.
Args:
data: dict of strings Mapping of string values to column names.
Returns:
Record which represents this row of the spreadsheet.
"""
new_row = self.client._GetSpreadsheetsClient().InsertRow(data,
self.spreadsheet_key, wksht_id=self.worksheet_id)
return Record(content=data, row_entry=new_row,
spreadsheet_key=self.spreadsheet_key, worksheet_id=self.worksheet_id,
database_client=self.client)
def GetRecord(self, row_id=None, row_number=None):
"""Gets a single record from the worksheet based on row ID or number.
Args:
row_id: The ID for the individual row.
row_number: str or int The position of the desired row. Numbering
begins at 1, which refers to the second row in the worksheet since
the first row is used for column names.
Returns:
Record for the desired row.
"""
if row_id:
row_entry = self.client._GetSpreadsheetsClient().GetListFeed(
self.spreadsheet_key, wksht_id=self.worksheet_id, row_id=row_id)
return Record(content=None, row_entry=row_entry,
spreadsheet_key=self.spreadsheet_key,
worksheet_id=self.worksheet_id, database_client=self.client)
else:
row_query = gdata.spreadsheet.service.ListQuery()
row_query.start_index = str(row_number)
row_query.max_results = '1'
row_feed = self.client._GetSpreadsheetsClient().GetListFeed(
self.spreadsheet_key, wksht_id=self.worksheet_id, query=row_query)
if len(row_feed.entry) >= 1:
return Record(content=None, row_entry=row_feed.entry[0],
spreadsheet_key=self.spreadsheet_key,
worksheet_id=self.worksheet_id, database_client=self.client)
else:
return None
def GetRecords(self, start_row, end_row):
"""Gets all rows between the start and end row numbers inclusive.
Args:
start_row: str or int
end_row: str or int
Returns:
RecordResultSet for the desired rows.
"""
start_row = int(start_row)
end_row = int(end_row)
max_rows = end_row - start_row + 1
row_query = gdata.spreadsheet.service.ListQuery()
row_query.start_index = str(start_row)
row_query.max_results = str(max_rows)
rows_feed = self.client._GetSpreadsheetsClient().GetListFeed(
self.spreadsheet_key, wksht_id=self.worksheet_id, query=row_query)
return RecordResultSet(rows_feed, self.client, self.spreadsheet_key,
self.worksheet_id)
def FindRecords(self, query_string):
"""Performs a query against the worksheet to find rows which match.
For details on query string syntax see the section on sq under
http://code.google.com/apis/spreadsheets/reference.html#list_Parameters
Args:
query_string: str Examples: 'name == john' to find all rows with john
in the name column, '(cost < 19.50 and name != toy) or cost > 500'
Returns:
RecordResultSet with the first group of matches.
"""
row_query = gdata.spreadsheet.service.ListQuery()
row_query.sq = query_string
matching_feed = self.client._GetSpreadsheetsClient().GetListFeed(
self.spreadsheet_key, wksht_id=self.worksheet_id, query=row_query)
return RecordResultSet(matching_feed, self.client,
self.spreadsheet_key, self.worksheet_id)
class RecordResultSet(list):
"""A collection of rows which allows fetching of the next set of results.
The server may not send all rows in the requested range because there are
too many. Using this result set you can access the first set of results
as if it is a list, then get the next batch (if there are more results) by
calling GetNext().
"""
def __init__(self, feed, client, spreadsheet_key, worksheet_id):
self.client = client
self.spreadsheet_key = spreadsheet_key
self.worksheet_id = worksheet_id
self.feed = feed
list(self)
for entry in self.feed.entry:
self.append(Record(content=None, row_entry=entry,
spreadsheet_key=spreadsheet_key, worksheet_id=worksheet_id,
database_client=client))
def GetNext(self):
"""Fetches the next batch of rows in the result set.
Returns:
A new RecordResultSet.
"""
next_link = self.feed.GetNextLink()
if next_link and next_link.href:
new_feed = self.client._GetSpreadsheetsClient().Get(next_link.href,
converter=gdata.spreadsheet.SpreadsheetsListFeedFromString)
return RecordResultSet(new_feed, self.client, self.spreadsheet_key,
self.worksheet_id)
class Record(object):
"""Represents one row in a worksheet and provides a dictionary of values.
Attributes:
custom: dict Represents the contents of the row with cell values mapped
to column headers.
"""
def __init__(self, content=None, row_entry=None, spreadsheet_key=None,
worksheet_id=None, database_client=None):
"""Constructor for a record.
Args:
content: dict of strings Mapping of string values to column names.
row_entry: gdata.spreadsheet.SpreadsheetsList The Atom entry
representing this row in the worksheet.
spreadsheet_key: str The ID of the spreadsheet in which this row
belongs.
worksheet_id: str The ID of the worksheet in which this row belongs.
database_client: DatabaseClient The client which can be used to talk
the Google Spreadsheets server to edit this row.
"""
self.entry = row_entry
self.spreadsheet_key = spreadsheet_key
self.worksheet_id = worksheet_id
if row_entry:
self.row_id = row_entry.id.text.split('/')[-1]
else:
self.row_id = None
self.client = database_client
self.content = content or {}
if not content:
self.ExtractContentFromEntry(row_entry)
def ExtractContentFromEntry(self, entry):
"""Populates the content and row_id based on content of the entry.
This method is used in the Record's contructor.
Args:
entry: gdata.spreadsheet.SpreadsheetsList The Atom entry
representing this row in the worksheet.
"""
self.content = {}
if entry:
self.row_id = entry.id.text.split('/')[-1]
for label, custom in entry.custom.iteritems():
self.content[label] = custom.text
def Push(self):
"""Send the content of the record to spreadsheets to edit the row.
All items in the content dictionary will be sent. Items which have been
removed from the content may remain in the row. The content member
of the record will not be modified so additional fields in the row
might be absent from this local copy.
"""
self.entry = self.client._GetSpreadsheetsClient().UpdateRow(self.entry, self.content)
def Pull(self):
"""Query Google Spreadsheets to get the latest data from the server.
Fetches the entry for this row and repopulates the content dictionary
with the data found in the row.
"""
if self.row_id:
self.entry = self.client._GetSpreadsheetsClient().GetListFeed(
self.spreadsheet_key, wksht_id=self.worksheet_id, row_id=self.row_id)
self.ExtractContentFromEntry(self.entry)
def Delete(self):
self.client._GetSpreadsheetsClient().DeleteRow(self.entry)
def ConvertStringsToColumnHeaders(proposed_headers):
"""Converts a list of strings to column names which spreadsheets accepts.
When setting values in a record, the keys which represent column names must
fit certain rules. They are all lower case, contain no spaces or special
characters. If two columns have the same name after being sanitized, the
columns further to the right have _2, _3 _4, etc. appended to them.
If there are column names which consist of all special characters, or if
the column header is blank, an obfuscated value will be used for a column
name. This method does not handle blank column names or column names with
only special characters.
"""
headers = []
for input_string in proposed_headers:
# TODO: probably a more efficient way to do this. Perhaps regex.
sanitized = input_string.lower().replace('_', '').replace(
':', '').replace(' ', '')
# When the same sanitized header appears multiple times in the first row
# of a spreadsheet, _n is appended to the name to make it unique.
header_count = headers.count(sanitized)
if header_count > 0:
headers.append('%s_%i' % (sanitized, header_count+1))
else:
headers.append(sanitized)
return headers