Add per-requirement --no-deps option support in requirements.txt

news/9948.feature.rst

@@ -0,0 +1 @@
+Add per-requirement ``--no-deps`` option support in requirements.txt.

src/pip/_internal/cli/req_command.py

@@ -345,6 +345,7 @@ def make_resolver(
         """
         make_install_req = partial(
             install_req_from_req_string,
+            ignore_dependencies=options.ignore_dependencies,
             isolated=options.isolated_mode,
             use_pep517=use_pep517,
         )

src/pip/_internal/commands/install.py

@@ -391,7 +391,11 @@ def run(self, options: Values, args: List[str]) -> int:
             # Check for conflicts in the package set we're installing.
             conflicts: Optional[ConflictDetails] = None
             should_warn_about_conflicts = (
-                not options.ignore_dependencies and options.warn_about_conflicts
+                not (
+                    options.ignore_dependencies
+                    or any((i for i in to_install if i.ignore_dependencies))
+                )
+                and options.warn_about_conflicts
             )
             if should_warn_about_conflicts:
                 conflicts = self._determine_conflicts(to_install)

src/pip/_internal/operations/check.py

@@ -100,7 +100,9 @@ def check_install_conflicts(to_install: List[InstallRequirement]) -> ConflictDet
     # Start from the current state
     package_set, _ = create_package_set_from_installed()
     # Install packages
-    would_be_installed = _simulate_installation_of(to_install, package_set)
+    would_be_installed = _simulate_installation_of(
+        [x for x in to_install if not x.ignore_dependencies], package_set
+    )
 
     # Only warn about directly-dependent packages; create a whitelist of them
     whitelist = _create_whitelist(would_be_installed, package_set)

src/pip/_internal/req/constructors.py

@@ -224,6 +224,9 @@ def install_req_from_editable(
         install_options=options.get("install_options", []) if options else [],
         global_options=options.get("global_options", []) if options else [],
         hash_options=options.get("hashes", {}) if options else {},
+        ignore_dependencies=options.get("ignore_dependencies", False)
+        if options
+        else False,
         extras=parts.extras,
     )
 
@@ -399,6 +402,9 @@ def install_req_from_line(
         install_options=options.get("install_options", []) if options else [],
         global_options=options.get("global_options", []) if options else [],
         hash_options=options.get("hashes", {}) if options else {},
+        ignore_dependencies=options.get("ignore_dependencies", False)
+        if options
+        else False,
         constraint=constraint,
         extras=parts.extras,
         user_supplied=user_supplied,
@@ -409,6 +415,7 @@ def install_req_from_req_string(
     req_string: str,
     comes_from: Optional[InstallRequirement] = None,
     isolated: bool = False,
+    ignore_dependencies: bool = False,
     use_pep517: Optional[bool] = None,
     user_supplied: bool = False,
 ) -> InstallRequirement:
@@ -438,6 +445,7 @@ def install_req_from_req_string(
         req,
         comes_from,
         isolated=isolated,
+        ignore_dependencies=ignore_dependencies,
         use_pep517=use_pep517,
         user_supplied=user_supplied,
     )
@@ -456,6 +464,7 @@ def install_req_from_parsed_requirement(
             use_pep517=use_pep517,
             constraint=parsed_req.constraint,
             isolated=isolated,
+            options=parsed_req.options,
             user_supplied=user_supplied,
         )
 
@@ -486,5 +495,6 @@ def install_req_from_link_and_ireq(
         isolated=ireq.isolated,
         install_options=ireq.install_options,
         global_options=ireq.global_options,
+        ignore_dependencies=ireq.ignore_dependencies,
         hash_options=ireq.hash_options,
     )

src/pip/_internal/req/req_file.py

@@ -72,6 +72,7 @@
     cmdoptions.install_options,
     cmdoptions.global_options,
     cmdoptions.hash,
+    cmdoptions.no_deps,
 ]
 
 # the 'dest' string values

src/pip/_internal/req/req_install.py

@@ -80,6 +80,7 @@ def __init__(
         install_options: Optional[List[str]] = None,
         global_options: Optional[List[str]] = None,
         hash_options: Optional[Dict[str, List[str]]] = None,
+        ignore_dependencies: bool = False,
         constraint: bool = False,
         extras: Collection[str] = (),
         user_supplied: bool = False,
@@ -138,6 +139,12 @@ def __init__(
         self.install_options = install_options if install_options else []
         self.global_options = global_options if global_options else []
         self.hash_options = hash_options if hash_options else {}
+        self.ignore_dependencies = ignore_dependencies
+        if (
+            isinstance(comes_from, InstallRequirement)
+            and comes_from.ignore_dependencies
+        ):
+            self.ignore_dependencies = True
         # Set to True after successful preparation of this requirement
         self.prepared = False
         # User supplied requirement are explicitly requested for installation

src/pip/_internal/resolution/resolvelib/base.py

@@ -131,6 +131,10 @@ def is_editable(self) -> bool:
     def source_link(self) -> Optional[Link]:
         raise NotImplementedError("Override in subclass")
 
+    @property
+    def ignore_dependencies(self) -> bool:
+        raise NotImplementedError("Override in subclass")
+
     def iter_dependencies(self, with_requires: bool) -> Iterable[Optional[Requirement]]:
         raise NotImplementedError("Override in subclass")
 

src/pip/_internal/resolution/resolvelib/candidates.py

@@ -68,6 +68,7 @@ def make_install_req_from_link(
             install_options=template.install_options,
             global_options=template.global_options,
             hashes=template.hash_options,
+            ignore_dependencies=template.ignore_dependencies,
         ),
     )
     ireq.original_link = template.original_link
@@ -91,6 +92,7 @@ def make_install_req_from_editable(
             install_options=template.install_options,
             global_options=template.global_options,
             hashes=template.hash_options,
+            ignore_dependencies=template.ignore_dependencies,
         ),
     )
 
@@ -115,6 +117,7 @@ def _make_install_req_from_dist(
             install_options=template.install_options,
             global_options=template.global_options,
             hashes=template.hash_options,
+            ignore_dependencies=template.ignore_dependencies,
         ),
     )
     ireq.satisfied_by = dist
@@ -239,6 +242,10 @@ def _prepare(self) -> BaseDistribution:
         self._check_metadata_consistency(dist)
         return dist
 
+    @property
+    def ignore_dependencies(self) -> bool:
+        return self._ireq.ignore_dependencies
+
     def iter_dependencies(self, with_requires: bool) -> Iterable[Optional[Requirement]]:
         requires = self.dist.iter_dependencies() if with_requires else ()
         for r in requires:
@@ -377,6 +384,10 @@ def version(self) -> CandidateVersion:
     def is_editable(self) -> bool:
         return self.dist.editable
 
+    @property
+    def ignore_dependencies(self) -> bool:
+        return self._ireq.ignore_dependencies
+
     def format_for_error(self) -> str:
         return f"{self.name} {self.version} (Installed)"
 
@@ -472,6 +483,10 @@ def is_editable(self) -> bool:
     def source_link(self) -> Optional[Link]:
         return self.base.source_link
 
+    @property
+    def ignore_dependencies(self) -> bool:
+        return self.base.ignore_dependencies
+
     def iter_dependencies(self, with_requires: bool) -> Iterable[Optional[Requirement]]:
         factory = self.base._factory
 
@@ -510,6 +525,7 @@ def get_install_requirement(self) -> Optional[InstallRequirement]:
 class RequiresPythonCandidate(Candidate):
     is_installed = False
     source_link = None
+    ignore_dependencies = False
 
     def __init__(self, py_version_info: Optional[Tuple[int, ...]]) -> None:
         if py_version_info is not None:

src/pip/_internal/resolution/resolvelib/provider.py

@@ -233,7 +233,7 @@ def is_satisfied_by(self, requirement: Requirement, candidate: Candidate) -> boo
         return requirement.is_satisfied_by(candidate)
 
     def get_dependencies(self, candidate: Candidate) -> Sequence[Requirement]:
-        with_requires = not self._ignore_dependencies
+        with_requires = not (self._ignore_dependencies or candidate.ignore_dependencies)
         return [r for r in candidate.iter_dependencies(with_requires) if r is not None]
 
     @staticmethod

tests/functional/test_install_reqs.py

@@ -816,3 +816,38 @@ def test_location_related_install_option_fails(script: PipTestEnvironment) -> No
         expect_error=True,
     )
     assert "['--home'] from simple" in result.stderr
+
+
+def test_install_options_no_deps(script: PipTestEnvironment) -> None:
+    create_basic_wheel_for_package(
+        script, "A", "0.1.0", depends=["B==0.1.0"], extras={"C": ["C"]}
+    )
+    create_basic_wheel_for_package(script, "B", "0.1.0")
+    create_basic_wheel_for_package(script, "C", "0.1.0")
+
+    requirements_txt = script.scratch_path / "requirements.txt"
+    requirements_txt.write_text("A[C] --no-deps")
+
+    script.pip(
+        "install",
+        "--no-cache-dir",
+        "--find-links",
+        script.scratch_path,
+        "-r",
+        requirements_txt,
+        "--only-binary=:all:",
+    )
+    script.assert_installed(A="0.1.0")
+    script.assert_not_installed("B", "C")
+
+    # AlreadyInstalledCandidate should not install dependencies
+    script.pip(
+        "install",
+        "--no-cache-dir",
+        "--find-links",
+        script.scratch_path,
+        "-r",
+        requirements_txt,
+        "--only-binary=:all:",
+    )
+    script.assert_not_installed("B", "C")