university-final-iot-backend/env/lib/python3.6/site-packages/pip/_internal/configuration.py

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"""Configuration management setup
Some terminology:
- name
As written in config files.
- value
Value associated with a name
- key
Name combined with it's section (section.name)
- variant
A single word describing where the configuration key-value pair came from
"""
import locale
import logging
import os
from pip._vendor import six
from pip._vendor.six.moves import configparser
from pip._internal.exceptions import ConfigurationError
from pip._internal.locations import (
legacy_config_file, new_config_file, running_under_virtualenv,
site_config_files, venv_config_file,
)
from pip._internal.utils.misc import ensure_dir, enum
from pip._internal.utils.typing import MYPY_CHECK_RUNNING
if MYPY_CHECK_RUNNING:
from typing import Any, Dict, Iterable, List, NewType, Optional, Tuple
RawConfigParser = configparser.RawConfigParser # Shorthand
Kind = NewType("Kind", str)
logger = logging.getLogger(__name__)
# NOTE: Maybe use the optionx attribute to normalize keynames.
def _normalize_name(name):
# type: (str) -> str
"""Make a name consistent regardless of source (environment or file)
"""
name = name.lower().replace('_', '-')
if name.startswith('--'):
name = name[2:] # only prefer long opts
return name
def _disassemble_key(name):
# type: (str) -> List[str]
return name.split(".", 1)
# The kinds of configurations there are.
kinds = enum(
USER="user", # User Specific
GLOBAL="global", # System Wide
VENV="venv", # Virtual Environment Specific
ENV="env", # from PIP_CONFIG_FILE
ENV_VAR="env-var", # from Environment Variables
)
class Configuration(object):
"""Handles management of configuration.
Provides an interface to accessing and managing configuration files.
This class converts provides an API that takes "section.key-name" style
keys and stores the value associated with it as "key-name" under the
section "section".
This allows for a clean interface wherein the both the section and the
key-name are preserved in an easy to manage form in the configuration files
and the data stored is also nice.
"""
def __init__(self, isolated, load_only=None):
# type: (bool, Kind) -> None
super(Configuration, self).__init__()
_valid_load_only = [kinds.USER, kinds.GLOBAL, kinds.VENV, None]
if load_only not in _valid_load_only:
raise ConfigurationError(
"Got invalid value for load_only - should be one of {}".format(
", ".join(map(repr, _valid_load_only[:-1]))
)
)
self.isolated = isolated # type: bool
self.load_only = load_only # type: Optional[Kind]
# The order here determines the override order.
self._override_order = [
kinds.GLOBAL, kinds.USER, kinds.VENV, kinds.ENV, kinds.ENV_VAR
]
self._ignore_env_names = ["version", "help"]
# Because we keep track of where we got the data from
self._parsers = {
variant: [] for variant in self._override_order
} # type: Dict[Kind, List[Tuple[str, RawConfigParser]]]
self._config = {
variant: {} for variant in self._override_order
} # type: Dict[Kind, Dict[str, Any]]
self._modified_parsers = [] # type: List[Tuple[str, RawConfigParser]]
def load(self):
# type: () -> None
"""Loads configuration from configuration files and environment
"""
self._load_config_files()
if not self.isolated:
self._load_environment_vars()
def get_file_to_edit(self):
# type: () -> Optional[str]
"""Returns the file with highest priority in configuration
"""
assert self.load_only is not None, \
"Need to be specified a file to be editing"
try:
return self._get_parser_to_modify()[0]
except IndexError:
return None
def items(self):
# type: () -> Iterable[Tuple[str, Any]]
"""Returns key-value pairs like dict.items() representing the loaded
configuration
"""
return self._dictionary.items()
def get_value(self, key):
# type: (str) -> Any
"""Get a value from the configuration.
"""
try:
return self._dictionary[key]
except KeyError:
raise ConfigurationError("No such key - {}".format(key))
def set_value(self, key, value):
# type: (str, Any) -> None
"""Modify a value in the configuration.
"""
self._ensure_have_load_only()
fname, parser = self._get_parser_to_modify()
if parser is not None:
section, name = _disassemble_key(key)
# Modify the parser and the configuration
if not parser.has_section(section):
parser.add_section(section)
parser.set(section, name, value)
self._config[self.load_only][key] = value
self._mark_as_modified(fname, parser)
def unset_value(self, key):
# type: (str) -> None
"""Unset a value in the configuration.
"""
self._ensure_have_load_only()
if key not in self._config[self.load_only]:
raise ConfigurationError("No such key - {}".format(key))
fname, parser = self._get_parser_to_modify()
if parser is not None:
section, name = _disassemble_key(key)
# Remove the key in the parser
modified_something = False
if parser.has_section(section):
# Returns whether the option was removed or not
modified_something = parser.remove_option(section, name)
if modified_something:
# name removed from parser, section may now be empty
section_iter = iter(parser.items(section))
try:
val = six.next(section_iter)
except StopIteration:
val = None
if val is None:
parser.remove_section(section)
self._mark_as_modified(fname, parser)
else:
raise ConfigurationError(
"Fatal Internal error [id=1]. Please report as a bug."
)
del self._config[self.load_only][key]
def save(self):
# type: () -> None
"""Save the currentin-memory state.
"""
self._ensure_have_load_only()
for fname, parser in self._modified_parsers:
logger.info("Writing to %s", fname)
# Ensure directory exists.
ensure_dir(os.path.dirname(fname))
with open(fname, "w") as f:
parser.write(f) # type: ignore
#
# Private routines
#
def _ensure_have_load_only(self):
# type: () -> None
if self.load_only is None:
raise ConfigurationError("Needed a specific file to be modifying.")
logger.debug("Will be working with %s variant only", self.load_only)
@property
def _dictionary(self):
# type: () -> Dict[str, Any]
"""A dictionary representing the loaded configuration.
"""
# NOTE: Dictionaries are not populated if not loaded. So, conditionals
# are not needed here.
retval = {}
for variant in self._override_order:
retval.update(self._config[variant])
return retval
def _load_config_files(self):
# type: () -> None
"""Loads configuration from configuration files
"""
config_files = dict(self._iter_config_files())
if config_files[kinds.ENV][0:1] == [os.devnull]:
logger.debug(
"Skipping loading configuration files due to "
"environment's PIP_CONFIG_FILE being os.devnull"
)
return
for variant, files in config_files.items():
for fname in files:
# If there's specific variant set in `load_only`, load only
# that variant, not the others.
if self.load_only is not None and variant != self.load_only:
logger.debug(
"Skipping file '%s' (variant: %s)", fname, variant
)
continue
parser = self._load_file(variant, fname)
# Keeping track of the parsers used
self._parsers[variant].append((fname, parser))
def _load_file(self, variant, fname):
# type: (Kind, str) -> RawConfigParser
logger.debug("For variant '%s', will try loading '%s'", variant, fname)
parser = self._construct_parser(fname)
for section in parser.sections():
items = parser.items(section)
self._config[variant].update(self._normalized_keys(section, items))
return parser
def _construct_parser(self, fname):
# type: (str) -> RawConfigParser
parser = configparser.RawConfigParser()
# If there is no such file, don't bother reading it but create the
# parser anyway, to hold the data.
# Doing this is useful when modifying and saving files, where we don't
# need to construct a parser.
if os.path.exists(fname):
try:
parser.read(fname)
except UnicodeDecodeError:
raise ConfigurationError((
"ERROR: "
"Configuration file contains invalid %s characters.\n"
"Please fix your configuration, located at %s\n"
) % (locale.getpreferredencoding(False), fname))
return parser
def _load_environment_vars(self):
# type: () -> None
"""Loads configuration from environment variables
"""
self._config[kinds.ENV_VAR].update(
self._normalized_keys(":env:", self._get_environ_vars())
)
def _normalized_keys(self, section, items):
# type: (str, Iterable[Tuple[str, Any]]) -> Dict[str, Any]
"""Normalizes items to construct a dictionary with normalized keys.
This routine is where the names become keys and are made the same
regardless of source - configuration files or environment.
"""
normalized = {}
for name, val in items:
key = section + "." + _normalize_name(name)
normalized[key] = val
return normalized
def _get_environ_vars(self):
# type: () -> Iterable[Tuple[str, str]]
"""Returns a generator with all environmental vars with prefix PIP_"""
for key, val in os.environ.items():
should_be_yielded = (
key.startswith("PIP_") and
key[4:].lower() not in self._ignore_env_names
)
if should_be_yielded:
yield key[4:].lower(), val
# XXX: This is patched in the tests.
def _iter_config_files(self):
# type: () -> Iterable[Tuple[Kind, List[str]]]
"""Yields variant and configuration files associated with it.
This should be treated like items of a dictionary.
"""
# SMELL: Move the conditions out of this function
# environment variables have the lowest priority
config_file = os.environ.get('PIP_CONFIG_FILE', None)
if config_file is not None:
yield kinds.ENV, [config_file]
else:
yield kinds.ENV, []
# at the base we have any global configuration
yield kinds.GLOBAL, list(site_config_files)
# per-user configuration next
should_load_user_config = not self.isolated and not (
config_file and os.path.exists(config_file)
)
if should_load_user_config:
# The legacy config file is overridden by the new config file
yield kinds.USER, [legacy_config_file, new_config_file]
# finally virtualenv configuration first trumping others
if running_under_virtualenv():
yield kinds.VENV, [venv_config_file]
def _get_parser_to_modify(self):
# type: () -> Tuple[str, RawConfigParser]
# Determine which parser to modify
parsers = self._parsers[self.load_only]
if not parsers:
# This should not happen if everything works correctly.
raise ConfigurationError(
"Fatal Internal error [id=2]. Please report as a bug."
)
# Use the highest priority parser.
return parsers[-1]
# XXX: This is patched in the tests.
def _mark_as_modified(self, fname, parser):
# type: (str, RawConfigParser) -> None
file_parser_tuple = (fname, parser)
if file_parser_tuple not in self._modified_parsers:
self._modified_parsers.append(file_parser_tuple)