"""
R help system.
"""
import os
from collections import namedtuple
import sqlite3
import rpy2.rinterface as rinterface
from rpy2.rinterface import StrSexpVector
from rpy2.robjects.packages_utils import (get_packagepath,
_libpaths,
_packages)
from collections import OrderedDict
tmp = rinterface.baseenv['R.Version']()
tmp_major = int(tmp[tmp.do_slot('names').index('major')][0])
tmp_minor = float(tmp[tmp.do_slot('names').index('minor')][0])
readRDS = rinterface.baseenv['readRDS']
del(tmp)
del(tmp_major)
del(tmp_minor)
_eval = rinterface.baseenv['eval']
def quiet_require(name, lib_loc=None):
""" Load an R package /quietly/ (suppressing messages to the console). """
if lib_loc is None:
lib_loc = "NULL"
expr_txt = ('suppressPackageStartupMessages(base::require(%s, lib.loc=%s))'
% (name, lib_loc))
expr = rinterface.parse(expr_txt)
ok = _eval(expr)
return ok
quiet_require('tools')
_get_namespace = rinterface.baseenv['getNamespace']
_lazyload_dbfetch = rinterface.baseenv['lazyLoadDBfetch']
tools_ns = _get_namespace(StrSexpVector(('tools',)))
_Rd_db = tools_ns['Rd_db']
_Rd_deparse = tools_ns['.Rd_deparse']
__rd_meta = os.path.join('Meta', 'Rd.rds')
__package_meta = os.path.join('Meta', 'package.rds')
def create_metaRd_db(dbcon):
""" Create an database to store R help pages.
dbcon: database connection (assumed to be SQLite - may or may not work
with other databases)
"""
dbcon.execute('''
CREATE TABLE package (
name TEXT UNIQUE,
title TEXT,
version TEXT,
description TEXT
);
''')
dbcon.execute('''
CREATE TABLE rd_meta (
id INTEGER, file TEXT UNIQUE, name TEXT, type TEXT, title TEXT, encoding TEXT,
package_rowid INTEGER
);
''')
dbcon.execute('''
CREATE INDEX type_idx ON rd_meta (type);
''')
dbcon.execute('''
CREATE TABLE rd_alias_meta (
rd_meta_rowid INTEGER, alias TEXT
);
''')
dbcon.execute('''
CREATE INDEX alias_idx ON rd_alias_meta (alias);
''')
dbcon.commit()
def populate_metaRd_db(package_name, dbcon, package_path=None):
""" Populate a database with the meta-information
associated with an R package: version, description, title, and
aliases (those are what the R help system is organised around).
- package_name: a string
- dbcon: a database connection
- package_path: path the R package installation (default: None)
"""
if package_path is None:
package_path = get_packagepath(package_name)
rpath = StrSexpVector((os.path.join(package_path,
__package_meta),))
rds = readRDS(rpath)
desc = rds[rds.do_slot('names').index('DESCRIPTION')]
db_res = dbcon.execute('insert into package values (?,?,?,?)',
(desc[desc.do_slot('names').index('Package')],
desc[desc.do_slot('names').index('Title')],
desc[desc.do_slot('names').index('Version')],
desc[desc.do_slot('names').index('Description')],
))
package_rowid = db_res.lastrowid
rpath = StrSexpVector((os.path.join(package_path,
__rd_meta),))
rds = readRDS(rpath)
FILE_I = rds.do_slot("names").index('File')
NAME_I = rds.do_slot("names").index('Name')
TYPE_I = rds.do_slot("names").index('Type')
TITLE_I = rds.do_slot("names").index('Title')
ENCODING_I = rds.do_slot("names").index('Encoding')
ALIAS_I = rds.do_slot("names").index('Aliases')
for row_i in range(len(rds[0])):
db_res = dbcon.execute('insert into rd_meta values (?,?,?,?,?,?,?)',
(row_i,
rds[FILE_I][row_i],
rds[NAME_I][row_i],
rds[TYPE_I][row_i],
rds[TITLE_I][row_i],
rds[ENCODING_I][row_i],
package_rowid))
rd_rowid = db_res.lastrowid
for alias in rds[ALIAS_I][row_i]:
dbcon.execute('insert into rd_alias_meta values (?,?)',
(rd_rowid, alias))
Item = namedtuple('Item', 'name value')
[docs]class Page(object):
""" An R documentation page.
The original R structure is a nested sequence of components,
corresponding to the latex-like .Rd file
An help page is divided into sections, the names for the sections
are the keys for the dict attribute 'sections', and a given section
can be extracted with the square-bracket operator.
In R, the S3 class 'Rd' is the closest entity to this class.
"""
def __init__(self, struct_rdb, _type=''):
sections = OrderedDict()
for elt in struct_rdb:
rd_tag = elt.do_slot("Rd_tag")[0][1:]
if rd_tag == 'section':
rd_section = rd_tag[0]
lst = sections.get(rd_tag)
if lst is None:
lst = []
sections[rd_tag] = lst
for sub_elt in elt:
lst.append(sub_elt)
self._sections = sections
self._type = _type
def _section_get(self):
return self._sections
sections = property(_section_get, None,
"Sections in the in help page, as a dict.")
def __getitem__(self, item):
""" Get a section """
return self.sections[item]
[docs] def arguments(self):
""" Get the arguments and their description as a list of tuples. """
section = self._sections.get('arguments')
res = list()
if section is None:
return res
for item in section:
if item.do_slot("Rd_tag")[0] == '\\item':
if len(item) != 2:
continue
arg_name = _Rd_deparse(item[0])[0]
arg_desc = _Rd_deparse(item[1])[0]
for x in arg_name.split(','):
x = x.lstrip()
if x.endswith('\\dots'):
x = '...'
res.append(Item(x, arg_desc))
else:
continue
return res
[docs] def description(self):
""" Get the description of the entry """
section = self._sections.get('description', None)
if section is None:
return ''
else:
res = ''.join(_Rd_deparse(x)[0] for x in section)
return res
[docs] def title(self):
""" Get the title """
section = self._sections['title']
res = ''.join(_Rd_deparse(x)[0] for x in section)
return res
[docs] def value(self):
""" Get the value returned """
section = self._sections.get('value', None)
if section is None:
return ''
else:
res = ''.join(_Rd_deparse(x)[0] for x in section)
return res
[docs] def seealso(self):
""" Get the other documentation entries recommended """
section = self._sections.get('seealso', None)
if section is None:
return ''
else:
res = ''.join(_Rd_deparse(x)[0] for x in section)
return res
[docs] def usage(self):
""" Get the usage for the object """
section = self._sections.get('usage', None)
if section is None:
res = ''
else:
res = (_Rd_deparse(x)[0] for x in section)
res = ''.join(res)
return res
[docs] def iteritems(self):
""" iterator through the sections names and content
in the documentation Page. """
return self.sections.iteritems
[docs] def to_docstring(self, section_names=None):
""" section_names: list of section names to consider. If None
all sections are used.
Returns a string that can be used as a Python docstring. """
s = []
if section_names is None:
section_names = self.sections.keys()
def walk(tree):
if not isinstance(tree, str):
for elt in tree:
walk(elt)
else:
s.append(tree)
s.append(' ')
for name in section_names:
s.append(name)
s.append(os.linesep)
s.append('-' * len(name))
s.append(os.linesep)
s.append(os.linesep)
walk(self.sections[name])
s.append(os.linesep)
s.append(os.linesep)
return ''.join(s)
[docs]class Package(object):
"""
The R documentation page (aka help) for a package.
"""
__package_path = None
__package_name = None
__aliases_info = 'aliases.rds'
__hsearch_meta = os.path.join('Meta', 'hsearch.rds')
__paths_info = 'paths.rds'
__anindex_info = 'AnIndex'
def __package_name_get(self):
return self.__package_name
name = property(__package_name_get, None, None,
'Name of the package as known by R')
def __init__(self, package_name, package_path=None):
self.__package_name = package_name
if package_path is None:
package_path = get_packagepath(package_name)
self.__package_path = package_path
rd_meta_dbcon = sqlite3.connect(':memory:')
create_metaRd_db(rd_meta_dbcon)
populate_metaRd_db(package_name,
rd_meta_dbcon,
package_path=package_path)
self._dbcon = rd_meta_dbcon
path = os.path.join(package_path, 'help', package_name + '.rdx')
self._rdx = readRDS(StrSexpVector((path, )))
[docs] def fetch(self, alias):
""" Fetch the documentation page associated with a given alias.
For S4 classes, the class name is *often* suffixed with '-class'.
For example, the alias to the documentation for the class
AnnotatedDataFrame in the package Biobase is
'AnnotatedDataFrame-class'.
"""
c = self._dbcon.execute(
'SELECT rd_meta_rowid, alias FROM rd_alias_meta WHERE alias=?',
(alias, )
)
res_alias = c.fetchall()
if len(res_alias) == 0:
raise HelpNotFoundError(
'No help could be fetched',
topic=alias, package=self.__package_name
)
c = self._dbcon.execute(
'SELECT file, name, type FROM rd_meta WHERE rowid=?',
(res_alias[0][0], )
)
# since the selection is on a verified rowid we are sure to
# exactly get one row
res = c.fetchall()
rkey = StrSexpVector((res[0][0][:-3], ))
_type = res[0][2]
rpath = StrSexpVector((os.path.join(self.package_path,
'help',
self.__package_name + '.rdb'),))
rdx_variables = (
self._rdx[self._rdx.do_slot('names').index('variables')]
)
_eval = rinterface.baseenv['eval']
devnull_func = rinterface.parse('function(x) {}')
devnull_func = _eval(devnull_func)
res = _lazyload_dbfetch(
rdx_variables[rdx_variables.do_slot('names').index(rkey[0])],
rpath,
self._rdx[self._rdx.do_slot('names').index("compressed")],
devnull_func
)
p_res = Page(res, _type=_type)
return p_res
package_path = property(lambda self: str(self.__package_path),
None, None,
'Path to the installed R package')
def __repr__(self):
r = 'R package %s %s' % (self.__package_name,
super(Package, self).__repr__())
return r
class HelpNotFoundError(KeyError):
""" Exception raised when an help topic cannot be found. """
def __init__(self, msg, topic=None, package=None):
super(HelpNotFoundError, self).__init__(msg)
self.topic = topic
self.package = package
[docs]def pages(topic):
""" Get help pages corresponding to a given topic. """
res = list()
for path in _libpaths():
for name in _packages(**{'all.available': True,
'lib.loc': StrSexpVector((path,))}):
# TODO: what if the same package is installed
# at different locations ?
pack = Package(name)
try:
page = pack.fetch(topic)
res.append(page)
except HelpNotFoundError as hnfe:
pass
return tuple(res)
def docstring(package, alias, sections=['usage', 'arguments']):
if not isinstance(package, Package):
package = Package(package)
page = package.fetch(alias)
return page.to_docstring(sections)
