Force resolving dependency via pip

README.md

@@ -368,6 +368,13 @@ python = "3.9"
 ampel-ztf = {version = "^0.8.0-alpha.2", source = "pypi"}
 ```
 
+A dependency will also be treated as a `pip` dependency if explicitly marked with `source = "pypi"` in the `[tool.conda-lock.dependencies]` section, e.g.:
+
+```toml
+[tool.conda-lock.dependencies]
+ampel-ztf = {source = "pypi"}
+```
+
 In both these cases, the dependencies of `pip`-installable packages will also be
 installed with `pip`, unless they were already requested by a `conda`
 dependency.

conda_lock/src_parser/pyproject_toml.py

@@ -162,23 +162,32 @@ def parse_poetry_pyproject_toml(
 def specification_with_dependencies(
     path: pathlib.Path, toml_contents: Mapping[str, Any], dependencies: List[Dependency]
 ) -> LockSpecification:
+    force_pypi = set()
     for depname, depattrs in get_in(
         ["tool", "conda-lock", "dependencies"], toml_contents, {}
     ).items():
         if isinstance(depattrs, str):
             conda_version = depattrs
+            dependencies.append(
+                VersionedDependency(
+                    name=depname,
+                    version=conda_version,
+                    manager="conda",
+                    optional=False,
+                    category="main",
+                    extras=[],
+                )
+            )
+        elif isinstance(depattrs, collections.abc.Mapping):
+            if depattrs.get("source", None) == "pypi":
+                force_pypi.add(depname)
         else:
             raise TypeError(f"Unsupported type for dependency: {depname}: {depattrs:r}")
-        dependencies.append(
-            VersionedDependency(
-                name=depname,
-                version=conda_version,
-                manager="conda",
-                optional=False,
-                category="main",
-                extras=[],
-            )
-        )
+
+    if force_pypi:
+        for dep in dependencies:
+            if dep.name in force_pypi:
+                dep.manager = "pip"
 
     return LockSpecification(
         dependencies=dependencies,

docs/src_pyproject.md

@@ -170,5 +170,17 @@ the following sections to the `pyproject.toml`
 sqlite = ">=3.34"
 ```
 
+### Force pypi dependencies
+
+While it is with poetry, it is not possible to indicate a package's source in a `pyproject.toml` which follows PEP621.
+
+In that case, it is possible to force resolving a dependency as a pip dependency by indicating it in the same `pyproject.toml` section.
+
+This is useful in particular for packages that are not present on conda channels.
+
+```{.toml title="pyproject.toml"}
+[tool.conda-lock.dependencies]
+numpy = {source = "pypi"}
+```
 
 [mapping]: https://github.com/regro/cf-graph-countyfair/blob/master/mappings/pypi/grayskull_pypi_mapping.yaml

tests/test-flit/pyproject.toml

@@ -25,3 +25,4 @@ channels = [
 [tool.conda-lock.dependencies]
 sqlite = "<3.34"
 certifi = ">=2019.11.28"
+toml = {source = "pypi"}

tests/test_conda_lock.py

@@ -442,6 +442,8 @@ def test_parse_flit(flit_pyproject_toml: Path):
     assert specs["pytest"].optional is True
     assert specs["pytest"].category == "dev"
 
+    assert specs["toml"].manager == "pip"
+
     assert res.channels == [Channel.from_string("defaults")]