Use pip_requirements_parser

.pre-commit-config.yaml

@@ -25,7 +25,7 @@ repos:
       - id: mypy
         args: ["--strict"]
         exclude: '^(docs|tasks|tests)|setup\.py'
-        additional_dependencies: ["httpx", "packaging", "typer>=0.3.2"]
+        additional_dependencies: ["packaging", "typer>=0.3.2"]
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
     rev: v0.0.270

news/107.misc

@@ -0,0 +1,2 @@
+Use `pip-requirements-parser <https://pypi.org/project/pip-requirements-parser/>`_
+instead of our own copy of pip's parser.

pyproject.toml

@@ -25,8 +25,8 @@ classifiers = [
 ]
 requires-python = ">=3.7"
 dependencies=[
-    "httpx",
     "packaging>=23",
+    "pip-requirements-parser",
     "tomli ; python_version<'3.11'",
     "typer[all]>=0.3.2",
     "typing-extensions ; python_version<'3.8'",  # for Protocol, TypedDict

src/pip_deepfreeze/pip.py

@@ -5,6 +5,7 @@
 
 from packaging.utils import NormalizedName
 from packaging.version import Version
+from pip_requirements_parser import RequirementsFile  # type: ignore[import]
 
 from .compat import TypedDict, shlex_join
 from .installed_dist import (
@@ -17,11 +18,6 @@
     list_installed_depends_by_extra,
 )
 from .project_name import get_project_name
-from .req_file_parser import (
-    NestedRequirementsLine,
-    RequirementLine,
-    parse as parse_req_file,
-)
 from .req_parser import get_req_name
 from .sanity import get_pip_version
 from .utils import (
@@ -73,14 +69,14 @@ def pip_upgrade_project(
     """
     # 1. parse constraints
     constraint_reqs = {}
-    for req_line in parse_req_file(
-        str(constraints_filename), recurse=False, reqs_only=False
-    ):
-        assert not isinstance(req_line, NestedRequirementsLine)
-        if isinstance(req_line, RequirementLine):
-            req_name = get_req_name(req_line.requirement)
-            assert req_name  # XXX user error instead?
-            constraint_reqs[req_name] = normalize_req_line(req_line.requirement)
+    parsed_constraints_file = RequirementsFile.from_file(
+        str(constraints_filename), include_nested=False
+    )
+    for constraint_req in parsed_constraints_file.requirements:
+        assert constraint_req.name  # XXX user error instead?
+        constraint_reqs[constraint_req.name] = normalize_req_line(
+            constraint_req.requirement_line.line
+        )
     # 2. get installed frozen dependencies of project
     installed_reqs = {
         get_req_name(req_line): normalize_req_line(req_line)