Mini Shell
"""
Requirements file parsing
"""
import optparse
import os
import re
import shlex
import urllib.parse
from optparse import Values
from typing import (
TYPE_CHECKING,
Any,
Callable,
Dict,
Iterable,
Iterator,
List,
Optional,
Tuple,
)
from pip._internal.cli import cmdoptions
from pip._internal.exceptions import InstallationError, RequirementsFileParseError
from pip._internal.models.search_scope import SearchScope
from pip._internal.network.session import PipSession
from pip._internal.network.utils import raise_for_status
from pip._internal.utils.encoding import auto_decode
from pip._internal.utils.urls import get_url_scheme
if TYPE_CHECKING:
# NoReturn introduced in 3.6.2; imported only for type checking to maintain
# pip compatibility with older patch versions of Python 3.6
from typing import NoReturn
from pip._internal.index.package_finder import PackageFinder
__all__ = ["parse_requirements"]
ReqFileLines = Iterable[Tuple[int, str]]
LineParser = Callable[[str], Tuple[str, Values]]
SCHEME_RE = re.compile(r"^(http|https|file):", re.I)
COMMENT_RE = re.compile(r"(^|\s+)#.*$")
# Matches environment variable-style values in '${MY_VARIABLE_1}' with the
# variable name consisting of only uppercase letters, digits or the '_'
# (underscore). This follows the POSIX standard defined in IEEE Std 1003.1,
# 2013 Edition.
ENV_VAR_RE = re.compile(r"(?P<var>\$\{(?P<name>[A-Z0-9_]+)\})")
SUPPORTED_OPTIONS: List[Callable[..., optparse.Option]] = [
cmdoptions.index_url,
cmdoptions.extra_index_url,
cmdoptions.no_index,
cmdoptions.constraints,
cmdoptions.requirements,
cmdoptions.editable,
cmdoptions.find_links,
cmdoptions.no_binary,
cmdoptions.only_binary,
cmdoptions.prefer_binary,
cmdoptions.require_hashes,
cmdoptions.pre,
cmdoptions.trusted_host,
cmdoptions.use_new_feature,
]
# options to be passed to requirements
SUPPORTED_OPTIONS_REQ: List[Callable[..., optparse.Option]] = [
cmdoptions.install_options,
cmdoptions.global_options,
cmdoptions.hash,
]
# the 'dest' string values
SUPPORTED_OPTIONS_REQ_DEST = [str(o().dest) for o in SUPPORTED_OPTIONS_REQ]
class ParsedRequirement:
def __init__(
self,
requirement: str,
is_editable: bool,
comes_from: str,
constraint: bool,
options: Optional[Dict[str, Any]] = None,
line_source: Optional[str] = None,
) -> None:
self.requirement = requirement
self.is_editable = is_editable
self.comes_from = comes_from
self.options = options
self.constraint = constraint
self.line_source = line_source
class ParsedLine:
def __init__(
self,
filename: str,
lineno: int,
args: str,
opts: Values,
constraint: bool,
) -> None:
self.filename = filename
self.lineno = lineno
self.opts = opts
self.constraint = constraint
if args:
self.is_requirement = True
self.is_editable = False
self.requirement = args
elif opts.editables:
self.is_requirement = True
self.is_editable = True
# We don't support multiple -e on one line
self.requirement = opts.editables[0]
else:
self.is_requirement = False
def parse_requirements(
filename: str,
session: PipSession,
finder: Optional["PackageFinder"] = None,
options: Optional[optparse.Values] = None,
constraint: bool = False,
) -> Iterator[ParsedRequirement]:
"""Parse a requirements file and yield ParsedRequirement instances.
:param filename: Path or url of requirements file.
:param session: PipSession instance.
:param finder: Instance of pip.index.PackageFinder.
:param options: cli options.
:param constraint: If true, parsing a constraint file rather than
requirements file.
"""
line_parser = get_line_parser(finder)
parser = RequirementsFileParser(session, line_parser)
for parsed_line in parser.parse(filename, constraint):
parsed_req = handle_line(
parsed_line, options=options, finder=finder, session=session
)
if parsed_req is not None:
yield parsed_req
def preprocess(content: str) -> ReqFileLines:
"""Split, filter, and join lines, and return a line iterator
:param content: the content of the requirements file
"""
lines_enum: ReqFileLines = enumerate(content.splitlines(), start=1)
lines_enum = join_lines(lines_enum)
lines_enum = ignore_comments(lines_enum)
lines_enum = expand_env_variables(lines_enum)
return lines_enum
def handle_requirement_line(
line: ParsedLine,
options: Optional[optparse.Values] = None,
) -> ParsedRequirement:
# preserve for the nested code path
line_comes_from = "{} {} (line {})".format(
"-c" if line.constraint else "-r",
line.filename,
line.lineno,
)
assert line.is_requirement
if line.is_editable:
# For editable requirements, we don't support per-requirement
# options, so just return the parsed requirement.
return ParsedRequirement(
requirement=line.requirement,
is_editable=line.is_editable,
comes_from=line_comes_from,
constraint=line.constraint,
)
else:
if options:
# Disable wheels if the user has specified build options
cmdoptions.check_install_build_global(options, line.opts)
# get the options that apply to requirements
req_options = {}
for dest in SUPPORTED_OPTIONS_REQ_DEST:
if dest in line.opts.__dict__ and line.opts.__dict__[dest]:
req_options[dest] = line.opts.__dict__[dest]
line_source = f"line {line.lineno} of {line.filename}"
return ParsedRequirement(
requirement=line.requirement,
is_editable=line.is_editable,
comes_from=line_comes_from,
constraint=line.constraint,
options=req_options,
line_source=line_source,
)
def handle_option_line(
opts: Values,
filename: str,
lineno: int,
finder: Optional["PackageFinder"] = None,
options: Optional[optparse.Values] = None,
session: Optional[PipSession] = None,
) -> None:
if options:
# percolate options upward
if opts.require_hashes:
options.require_hashes = opts.require_hashes
if opts.features_enabled:
options.features_enabled.extend(
f for f in opts.features_enabled if f not in options.features_enabled
)
# set finder options
if finder:
find_links = finder.find_links
index_urls = finder.index_urls
if opts.index_url:
index_urls = [opts.index_url]
if opts.no_index is True:
index_urls = []
if opts.extra_index_urls:
index_urls.extend(opts.extra_index_urls)
if opts.find_links:
# FIXME: it would be nice to keep track of the source
# of the find_links: support a find-links local path
# relative to a requirements file.
value = opts.find_links[0]
req_dir = os.path.dirname(os.path.abspath(filename))
relative_to_reqs_file = os.path.join(req_dir, value)
if os.path.exists(relative_to_reqs_file):
value = relative_to_reqs_file
find_links.append(value)
if session:
# We need to update the auth urls in session
session.update_index_urls(index_urls)
search_scope = SearchScope(
find_links=find_links,
index_urls=index_urls,
)
finder.search_scope = search_scope
if opts.pre:
finder.set_allow_all_prereleases()
if opts.prefer_binary:
finder.set_prefer_binary()
if session:
for host in opts.trusted_hosts or []:
source = f"line {lineno} of {filename}"
session.add_trusted_host(host, source=source)
def handle_line(
line: ParsedLine,
options: Optional[optparse.Values] = None,
finder: Optional["PackageFinder"] = None,
session: Optional[PipSession] = None,
) -> Optional[ParsedRequirement]:
"""Handle a single parsed requirements line; This can result in
creating/yielding requirements, or updating the finder.
:param line: The parsed line to be processed.
:param options: CLI options.
:param finder: The finder - updated by non-requirement lines.
:param session: The session - updated by non-requirement lines.
Returns a ParsedRequirement object if the line is a requirement line,
otherwise returns None.
For lines that contain requirements, the only options that have an effect
are from SUPPORTED_OPTIONS_REQ, and they are scoped to the
requirement. Other options from SUPPORTED_OPTIONS may be present, but are
ignored.
For lines that do not contain requirements, the only options that have an
effect are from SUPPORTED_OPTIONS. Options from SUPPORTED_OPTIONS_REQ may
be present, but are ignored. These lines may contain multiple options
(although our docs imply only one is supported), and all our parsed and
affect the finder.
"""
if line.is_requirement:
parsed_req = handle_requirement_line(line, options)
return parsed_req
else:
handle_option_line(
line.opts,
line.filename,
line.lineno,
finder,
options,
session,
)
return None
class RequirementsFileParser:
def __init__(
self,
session: PipSession,
line_parser: LineParser,
) -> None:
self._session = session
self._line_parser = line_parser
def parse(self, filename: str, constraint: bool) -> Iterator[ParsedLine]:
"""Parse a given file, yielding parsed lines."""
yield from self._parse_and_recurse(filename, constraint)
def _parse_and_recurse(
self, filename: str, constraint: bool
) -> Iterator[ParsedLine]:
for line in self._parse_file(filename, constraint):
if not line.is_requirement and (
line.opts.requirements or line.opts.constraints
):
# parse a nested requirements file
if line.opts.requirements:
req_path = line.opts.requirements[0]
nested_constraint = False
else:
req_path = line.opts.constraints[0]
nested_constraint = True
# original file is over http
if SCHEME_RE.search(filename):
# do a url join so relative paths work
req_path = urllib.parse.urljoin(filename, req_path)
# original file and nested file are paths
elif not SCHEME_RE.search(req_path):
# do a join so relative paths work
req_path = os.path.join(
os.path.dirname(filename),
req_path,
)
yield from self._parse_and_recurse(req_path, nested_constraint)
else:
yield line
def _parse_file(self, filename: str, constraint: bool) -> Iterator[ParsedLine]:
_, content = get_file_content(filename, self._session)
lines_enum = preprocess(content)
for line_number, line in lines_enum:
try:
args_str, opts = self._line_parser(line)
except OptionParsingError as e:
# add offending line
msg = f"Invalid requirement: {line}\n{e.msg}"
raise RequirementsFileParseError(msg)
yield ParsedLine(
filename,
line_number,
args_str,
opts,
constraint,
)
def get_line_parser(finder: Optional["PackageFinder"]) -> LineParser:
def parse_line(line: str) -> Tuple[str, Values]:
# Build new parser for each line since it accumulates appendable
# options.
parser = build_parser()
defaults = parser.get_default_values()
defaults.index_url = None
if finder:
defaults.format_control = finder.format_control
args_str, options_str = break_args_options(line)
opts, _ = parser.parse_args(shlex.split(options_str), defaults)
return args_str, opts
return parse_line
def break_args_options(line: str) -> Tuple[str, str]:
"""Break up the line into an args and options string. We only want to shlex
(and then optparse) the options, not the args. args can contain markers
which are corrupted by shlex.
"""
tokens = line.split(" ")
args = []
options = tokens[:]
for token in tokens:
if token.startswith("-") or token.startswith("--"):
break
else:
args.append(token)
options.pop(0)
return " ".join(args), " ".join(options)
class OptionParsingError(Exception):
def __init__(self, msg: str) -> None:
self.msg = msg
def build_parser() -> optparse.OptionParser:
"""
Return a parser for parsing requirement lines
"""
parser = optparse.OptionParser(add_help_option=False)
option_factories = SUPPORTED_OPTIONS + SUPPORTED_OPTIONS_REQ
for option_factory in option_factories:
option = option_factory()
parser.add_option(option)
# By default optparse sys.exits on parsing errors. We want to wrap
# that in our own exception.
def parser_exit(self: Any, msg: str) -> "NoReturn":
raise OptionParsingError(msg)
# NOTE: mypy disallows assigning to a method
# https://github.com/python/mypy/issues/2427
parser.exit = parser_exit # type: ignore
return parser
def join_lines(lines_enum: ReqFileLines) -> ReqFileLines:
"""Joins a line ending in '\' with the previous line (except when following
comments). The joined line takes on the index of the first line.
"""
primary_line_number = None
new_line: List[str] = []
for line_number, line in lines_enum:
if not line.endswith("\\") or COMMENT_RE.match(line):
if COMMENT_RE.match(line):
# this ensures comments are always matched later
line = " " + line
if new_line:
new_line.append(line)
assert primary_line_number is not None
yield primary_line_number, "".join(new_line)
new_line = []
else:
yield line_number, line
else:
if not new_line:
primary_line_number = line_number
new_line.append(line.strip("\\"))
# last line contains \
if new_line:
assert primary_line_number is not None
yield primary_line_number, "".join(new_line)
# TODO: handle space after '\'.
def ignore_comments(lines_enum: ReqFileLines) -> ReqFileLines:
"""
Strips comments and filter empty lines.
"""
for line_number, line in lines_enum:
line = COMMENT_RE.sub("", line)
line = line.strip()
if line:
yield line_number, line
def expand_env_variables(lines_enum: ReqFileLines) -> ReqFileLines:
"""Replace all environment variables that can be retrieved via `os.getenv`.
The only allowed format for environment variables defined in the
requirement file is `${MY_VARIABLE_1}` to ensure two things:
1. Strings that contain a `$` aren't accidentally (partially) expanded.
2. Ensure consistency across platforms for requirement files.
These points are the result of a discussion on the `github pull
request #3514 <https://github.com/pypa/pip/pull/3514>`_.
Valid characters in variable names follow the `POSIX standard
<http://pubs.opengroup.org/onlinepubs/9699919799/>`_ and are limited
to uppercase letter, digits and the `_` (underscore).
"""
for line_number, line in lines_enum:
for env_var, var_name in ENV_VAR_RE.findall(line):
value = os.getenv(var_name)
if not value:
continue
line = line.replace(env_var, value)
yield line_number, line
def get_file_content(url: str, session: PipSession) -> Tuple[str, str]:
"""Gets the content of a file; it may be a filename, file: URL, or
http: URL. Returns (location, content). Content is unicode.
Respects # -*- coding: declarations on the retrieved files.
:param url: File path or url.
:param session: PipSession instance.
"""
scheme = get_url_scheme(url)
# Pip has special support for file:// URLs (LocalFSAdapter).
if scheme in ["http", "https", "file"]:
resp = session.get(url)
raise_for_status(resp)
return resp.url, resp.text
# Assume this is a bare path.
try:
with open(url, "rb") as f:
content = auto_decode(f.read())
except OSError as exc:
raise InstallationError(f"Could not open requirements file: {exc}")
return url, content
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