lpip.reqfile

src/lpip/reqfile.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
"""Parse a pip-style requirements file for ``lpip install -r`` (ADR-0017)."""

from __future__ import annotations

from collections.abc import Iterator
from pathlib import Path

from packaging.requirements import InvalidRequirement, Requirement
from packaging.version import InvalidVersion, Version

from lpip.errors import (
    CatalogExtrasNotSupportedError,
    RequirementsFileError,
    RequirementsParseError,
    UnsupportedCatalogSpecifierError,
)


def iter_requirement_lines(text: str) -> Iterator[str]:
    """Yield non-empty requirement lines; drop comments and blanks."""
    for raw in text.splitlines():
        stripped = raw.strip()
        if not stripped or stripped.startswith("#"):
            continue
        if " #" in stripped:
            stripped = stripped.split(" #", 1)[0].strip()
            if not stripped:
                continue
        yield stripped


def requirement_name(line: str) -> str:
    """Distribution name from a PEP 508 line. Reject pip option lines."""
    if line.startswith("-"):
        raise RequirementsFileError(
            f"Unsupported requirements option: {line}",
            hint="v1 install -r accepts PEP 508 requirement lines only "
            "(no -r, -e, or other pip flags).",
        )
    try:
        return Requirement(line).name
    except InvalidRequirement as exc:
        raise RequirementsParseError(line, detail=str(exc)) from exc


def parse_catalog_request(line: str) -> tuple[str, Version | None]:
    """Name plus optional == version for a catalog install (ADR-0018)."""
    name = requirement_name(line)
    try:
        req = Requirement(line)
    except InvalidRequirement as exc:
        raise RequirementsParseError(line, detail=str(exc)) from exc
    if req.extras:
        raise CatalogExtrasNotSupportedError(name)
    specs = list(req.specifier)
    if not specs:
        return name, None
    if len(specs) == 1 and specs[0].operator in {"==", "==="}:
        try:
            return name, Version(specs[0].version)
        except InvalidVersion as exc:
            raise RequirementsParseError(line, detail=str(exc)) from exc
    raise UnsupportedCatalogSpecifierError(line)


def load_requirement_lines(path: Path) -> tuple[str, ...]:
    file = path.expanduser()
    if not file.is_file():
        raise RequirementsFileError(
            f"Requirements file was not found: {file}",
            hint="Pass -r lpip-requirements.txt (or another existing path).",
            path=file,
        )
    return tuple(iter_requirement_lines(file.read_text(encoding="utf-8")))