pip/src/pip/_internal/utils/deprecation.py

90 lines
3.0 KiB
Python

"""
A module that implements tooling to enable easy warnings about deprecations.
"""
from __future__ import absolute_import
import logging
import warnings
from pip._vendor.packaging.version import parse
from pip import __version__ as current_version
from pip._internal.utils.typing import MYPY_CHECK_RUNNING
if MYPY_CHECK_RUNNING:
from typing import Any, Optional # noqa: F401
class PipDeprecationWarning(Warning):
pass
_original_showwarning = None # type: Any
# Warnings <-> Logging Integration
def _showwarning(message, category, filename, lineno, file=None, line=None):
if file is not None:
if _original_showwarning is not None:
_original_showwarning(
message, category, filename, lineno, file, line,
)
elif issubclass(category, PipDeprecationWarning):
# We use a specially named logger which will handle all of the
# deprecation messages for pip.
logger = logging.getLogger("pip._internal.deprecations")
logger.warning(message)
else:
_original_showwarning(
message, category, filename, lineno, file, line,
)
def install_warning_logger():
# Enable our Deprecation Warnings
warnings.simplefilter("default", PipDeprecationWarning, append=True)
global _original_showwarning
if _original_showwarning is None:
_original_showwarning = warnings.showwarning
warnings.showwarning = _showwarning
def deprecated(reason, replacement, gone_in, issue=None):
# type: (str, Optional[str], Optional[str], Optional[int]) -> None
"""Helper to deprecate existing functionality.
reason:
Textual reason shown to the user about why this functionality has
been deprecated.
replacement:
Textual suggestion shown to the user about what alternative
functionality they can use.
gone_in:
The version of pip does this functionality should get removed in.
Raises errors if pip's current version is greater than or equal to
this.
issue:
Issue number on the tracker that would serve as a useful place for
users to find related discussion and provide feedback.
Always pass replacement, gone_in and issue as keyword arguments for clarity
at the call site.
"""
# Construct a nice message.
# This is purposely eagerly formatted as we want it to appear as if someone
# typed this entire message out.
message = "DEPRECATION: " + reason
if replacement is not None:
message += " A possible replacement is {}.".format(replacement)
if issue is not None:
url = "https://github.com/pypa/pip/issues/" + str(issue)
message += " You can find discussion regarding this at {}.".format(url)
# Raise as an error if it has to be removed.
if gone_in is not None and parse(current_version) >= parse(gone_in):
raise PipDeprecationWarning(message)
warnings.warn(message, category=PipDeprecationWarning, stacklevel=2)