"""Discover and load entry points from installed packages."""
# Copyright (c) Thomas Kluyver and contributors
# Distributed under the terms of the MIT license; see LICENSE file.
from contextlib import contextmanager
import glob
from importlib import import_module
import io
import itertools
import os.path as osp
import re
import sys
import warnings
import zipfile
import configparser
entry_point_pattern = re.compile(r"""
(?P<modulename>\w+(\.\w+)*)
(:(?P<objectname>\w+(\.\w+)*))?
\s*
(\[(?P<extras>.+)\])?
$
""", re.VERBOSE)
file_in_zip_pattern = re.compile(r"""
(?P<dist_version>[^/\\]+)\.(dist|egg)-info
[/\\]entry_points.txt$
""", re.VERBOSE)
__version__ = '0.3'
class BadEntryPoint(Exception):
"""Raised when an entry point can't be parsed.
"""
def __init__(self, epstr):
self.epstr = epstr
def __str__(self):
return "Couldn't parse entry point spec: %r" % self.epstr
@staticmethod
@contextmanager
def err_to_warnings():
try:
yield
except BadEntryPoint as e:
warnings.warn(str(e))
class NoSuchEntryPoint(Exception):
"""Raised by :func:`get_single` when no matching entry point is found."""
def __init__(self, group, name):
self.group = group
self.name = name
def __str__(self):
return "No {!r} entry point found in group {!r}".format(self.name, self.group)
class CaseSensitiveConfigParser(configparser.ConfigParser):
optionxform = staticmethod(str)
class EntryPoint(object):
def __init__(self, name, module_name, object_name, extras=None, distro=None):
self.name = name
self.module_name = module_name
self.object_name = object_name
self.extras = extras
self.distro = distro
def __repr__(self):
return "EntryPoint(%r, %r, %r, %r)" % \
(self.name, self.module_name, self.object_name, self.distro)
def load(self):
"""Load the object to which this entry point refers.
"""
mod = import_module(self.module_name)
obj = mod
if self.object_name:
for attr in self.object_name.split('.'):
obj = getattr(obj, attr)
return obj
@classmethod
def from_string(cls, epstr, name, distro=None):
"""Parse an entry point from the syntax in entry_points.txt
:param str epstr: The entry point string (not including 'name =')
:param str name: The name of this entry point
:param Distribution distro: The distribution in which the entry point was found
:rtype: EntryPoint
:raises BadEntryPoint: if *epstr* can't be parsed as an entry point.
"""
m = entry_point_pattern.match(epstr)
if m:
mod, obj, extras = m.group('modulename', 'objectname', 'extras')
if extras is not None:
extras = re.split(r',\s*', extras)
return cls(name, mod, obj, extras, distro)
else:
raise BadEntryPoint(epstr)
class Distribution(object):
def __init__(self, name, version):
self.name = name
self.version = version
def __repr__(self):
return "Distribution(%r, %r)" % (self.name, self.version)
def iter_files_distros(path=None, repeated_distro='first'):
if path is None:
path = sys.path
# Distributions found earlier in path will shadow those with the same name
# found later. If these distributions used different module names, it may
# actually be possible to import both, but in most cases this shadowing
# will be correct.
distro_names_seen = set()
for folder in path:
if folder.rstrip('/\\').endswith('.egg'):
# Gah, eggs
egg_name = osp.basename(folder)
if '-' in egg_name:
distro = Distribution(*egg_name.split('-')[:2])
if (repeated_distro == 'first') \
and (distro.name in distro_names_seen):
continue
distro_names_seen.add(distro.name)
else:
distro = None
if osp.isdir(folder):
ep_path = osp.join(folder, 'EGG-INFO', 'entry_points.txt')
if osp.isfile(ep_path):
cp = CaseSensitiveConfigParser(delimiters=('=',))
cp.read([ep_path])
yield cp, distro
elif zipfile.is_zipfile(folder):
z = zipfile.ZipFile(folder)
try:
info = z.getinfo('EGG-INFO/entry_points.txt')
except KeyError:
continue
cp = CaseSensitiveConfigParser(delimiters=('=',))
with z.open(info) as f:
fu = io.TextIOWrapper(f)
cp.read_file(fu,
source=osp.join(folder, 'EGG-INFO', 'entry_points.txt'))
yield cp, distro
# zip imports, not egg
elif zipfile.is_zipfile(folder):
with zipfile.ZipFile(folder) as zf:
for info in zf.infolist():
m = file_in_zip_pattern.match(info.filename)
if not m:
continue
distro_name_version = m.group('dist_version')
if '-' in distro_name_version:
distro = Distribution(*distro_name_version.split('-', 1))
if (repeated_distro == 'first') \
and (distro.name in distro_names_seen):
continue
distro_names_seen.add(distro.name)
else:
distro = None
cp = CaseSensitiveConfigParser(delimiters=('=',))
with zf.open(info) as f:
fu = io.TextIOWrapper(f)
cp.read_file(fu, source=osp.join(folder, info.filename))
yield cp, distro
# Regular file imports (not egg, not zip file)
for path in itertools.chain(
glob.iglob(osp.join(folder, '*.dist-info', 'entry_points.txt')),
glob.iglob(osp.join(folder, '*.egg-info', 'entry_points.txt'))
):
distro_name_version = osp.splitext(osp.basename(osp.dirname(path)))[0]
if '-' in distro_name_version:
distro = Distribution(*distro_name_version.split('-', 1))
if (repeated_distro == 'first') \
and (distro.name in distro_names_seen):
continue
distro_names_seen.add(distro.name)
else:
distro = None
cp = CaseSensitiveConfigParser(delimiters=('=',))
cp.read([path])
yield cp, distro
def get_single(group, name, path=None):
"""Find a single entry point.
Returns an :class:`EntryPoint` object, or raises :exc:`NoSuchEntryPoint`
if no match is found.
"""
for config, distro in iter_files_distros(path=path):
if (group in config) and (name in config[group]):
epstr = config[group][name]
with BadEntryPoint.err_to_warnings():
return EntryPoint.from_string(epstr, name, distro)
raise NoSuchEntryPoint(group, name)
def get_group_named(group, path=None):
"""Find a group of entry points with unique names.
Returns a dictionary of names to :class:`EntryPoint` objects.
"""
result = {}
for ep in get_group_all(group, path=path):
if ep.name not in result:
result[ep.name] = ep
return result
def get_group_all(group, path=None):
"""Find all entry points in a group.
Returns a list of :class:`EntryPoint` objects.
"""
result = []
for config, distro in iter_files_distros(path=path):
if group in config:
for name, epstr in config[group].items():
with BadEntryPoint.err_to_warnings():
result.append(EntryPoint.from_string(epstr, name, distro))
return result
if __name__ == '__main__':
import pprint
pprint.pprint(get_group_all('console_scripts'))