def _handle_no_cache_dir(
option: Option, opt: str, value: str, parser: OptionParser
) -> None:
"""
Process a value provided for the --no-cache-dir option.
This is an optparse.Option callback for the --no-cache-dir option.
"""
# The value argument will be None if --no-cache-dir is passed via the
# command-line, since the option doesn't accept arguments. However,
# the value can be non-None if the option is triggered e.g. by an
# environment variable, like PIP_NO_CACHE_DIR=true.
if value is not None:
# Then parse the string value to get argument error-checking.
try:
strtobool(value)
except ValueError as exc:
raise_option_error(parser, option=option, msg=str(exc))
# Originally, setting PIP_NO_CACHE_DIR to a value that strtobool()
# converted to 0 (like "false" or "no") caused cache_dir to be disabled
# rather than enabled (logic would say the latter). Thus, we disable
# the cache directory not just on values that parse to True, but (for
# backwards compatibility reasons) also on values that parse to False.
# In other words, always set it to False if the option is provided in
# some (valid) form.
parser.values.cache_dir = False
def _update_defaults(self, defaults):
"""Updates the given defaults with values from the config files and
the environ. Does a little special handling for certain types of
options (lists)."""
# Accumulate complex default state.
self.values = optparse.Values(self.defaults)
late_eval = set()
# Then set the options with those values
for key, val in self._get_ordered_configuration_items():
# '--' because configuration supports only long names
option = self.get_option("--" + key)
# Ignore options not present in this parser. E.g. non-globals put
# in [global] by users that want them to apply to all applicable
# commands.
if option is None:
continue
if option.action in ("store_true", "store_false"):
try:
val = strtobool(val)
except ValueError:
self.error(
"{} is not a valid value for {} option, " # noqa
"please specify a boolean value like yes/no, "
"true/false or 1/0 instead.".format(val, key)
)
elif option.action == "count":
with suppress(ValueError):
val = strtobool(val)
with suppress(ValueError):
val = int(val)
if not isinstance(val, int) or val < 0:
self.error(
"{} is not a valid value for {} option, " # noqa
"please instead specify either a non-negative integer "
"or a boolean value like yes/no or false/true "
"which is equivalent to 1/0.".format(val, key)
)
elif option.action == "append":
val = val.split()
val = [self.check_default(option, key, v) for v in val]
elif option.action == "callback":
late_eval.add(option.dest)
opt_str = option.get_opt_string()
val = option.convert_value(opt_str, val)
# From take_action
args = option.callback_args or ()
kwargs = option.callback_kwargs or {}
option.callback(option, opt_str, val, self, *args, **kwargs)
else:
val = self.check_default(option, key, val)
defaults[option.dest] = val
for key in late_eval:
defaults[key] = getattr(self.values, key)
self.values = None
return defaults
def _should_use_importlib_metadata() -> bool:
"""Whether to use the ``importlib.metadata`` or ``pkg_resources`` backend.
By default, pip uses ``importlib.metadata`` on Python 3.11+, and
``pkg_resourcess`` otherwise. This can be overridden by a couple of ways:
* If environment variable ``_PIP_USE_IMPORTLIB_METADATA`` is set, it
dictates whether ``importlib.metadata`` is used, regardless of Python
version.
* On Python 3.11+, Python distributors can patch ``importlib.metadata``
to add a global constant ``_PIP_USE_IMPORTLIB_METADATA = False``. This
makes pip use ``pkg_resources`` (unless the user set the aforementioned
environment variable to *True*).
"""
with contextlib.suppress(KeyError, ValueError):
return bool(strtobool(os.environ["_PIP_USE_IMPORTLIB_METADATA"]))
if sys.version_info < (3, 11):
return False
import importlib.metadata
return bool(
getattr(importlib.metadata, "_PIP_USE_IMPORTLIB_METADATA", True))
