ENH Add support for reinstalling packages

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added `verbose` parameter to micropip.install and micropip.uninstall
   [#60](https://github.com/pyodide/micropip/pull/60)
 
+- Added `reinstall` parameter to micropip.install to allow reinstalling
+  a package that is already installed
+  [#64](https://github.com/pyodide/micropip/pull/64)
+
 ### Fixed
 
 - Fixed `micropip.add_mock_package` to work with Pyodide>=0.23.0

micropip/_commands/install.py

@@ -5,8 +5,9 @@
 from packaging.markers import default_environment
 
 from .._compat import loadPackage, to_js
+from .._uninstall import uninstall_distributions
 from ..constants import FAQ_URLS
-from ..logging import setup_logging
+from ..logging import indent_log, setup_logging
 from ..transaction import Transaction
 
 
@@ -16,6 +17,7 @@ async def install(
     deps: bool = True,
     credentials: str | None = None,
     pre: bool = False,
+    reinstall: bool = False,
     *,
     verbose: bool | int = False,
 ) -> None:
@@ -86,6 +88,10 @@ async def install(
         If ``True``, include pre-release and development versions. By default,
         micropip only finds stable versions.
 
+    reinstall :
+
+        If ``True``, reinstall packages if they are already installed.
+
     verbose :
         Print more information about the process.
         By default, micropip is silent. Setting ``verbose=True`` will print
@@ -115,6 +121,7 @@ async def install(
         keep_going=keep_going,
         deps=deps,
         pre=pre,
+        reinstall=reinstall,
         fetch_kwargs=fetch_kwargs,
         verbose=verbose,
     )
@@ -127,12 +134,23 @@ async def install(
             f"See: {FAQ_URLS['cant_find_wheel']}\n"
         )
 
-    package_names = [pkg.name for pkg in transaction.pyodide_packages] + [
-        pkg.name for pkg in transaction.wheels
-    ]
+    # uninstall packages that are installed
+    packages_all = set([pkg.name for pkg in transaction.wheels]) | set(
+        [pkg.name for pkg in transaction.pyodide_packages]
+    )
+
+    distributions = []
+    for pkg_name in packages_all:
+        try:
+            distributions.append(importlib.metadata.distribution(pkg_name))
+        except importlib.metadata.PackageNotFoundError:
+            pass
+
+    with indent_log():
+        uninstall_distributions(distributions)
 
-    if package_names:
-        logger.info("Installing collected packages: " + ", ".join(package_names))
+    if packages_all:
+        logger.info("Installing collected packages: " + ", ".join(packages_all))
 
     wheel_promises = []
     # Install built-in packages

micropip/_commands/uninstall.py

@@ -2,8 +2,7 @@
 import importlib.metadata
 from importlib.metadata import Distribution
 
-from .._compat import loadedPackages
-from .._utils import get_files_in_distribution, get_root
+from .._uninstall import uninstall_distributions
 from ..logging import setup_logging
 
 
@@ -41,57 +40,6 @@ def uninstall(packages: str | list[str], *, verbose: bool | int = False) -> None
         except importlib.metadata.PackageNotFoundError:
             logger.warning(f"Skipping '{package}' as it is not installed.")
 
-    for dist in distributions:
-        # Note: this value needs to be retrieved before removing files, as
-        #       dist.name uses metadata file to get the name
-        name = dist.name
-        version = dist.version
-
-        logger.info(f"Found existing installation: {name} {version}")
-
-        root = get_root(dist)
-        files = get_files_in_distribution(dist)
-        directories = set()
-
-        for file in files:
-            if not file.is_file():
-                if not file.is_relative_to(root):
-                    # This file is not in the site-packages directory. Probably one of:
-                    # - data_files
-                    # - scripts
-                    # - entry_points
-                    # Since we don't support these, we can ignore them (except for data_files (TODO))
-                    continue
-
-                logger.warning(
-                    f"A file '{file}' listed in the metadata of '{name}' does not exist.",
-                )
-
-                continue
-
-            file.unlink()
-
-            if file.parent != root:
-                directories.add(file.parent)
-
-        # Remove directories in reverse hierarchical order
-        for directory in sorted(directories, key=lambda x: len(x.parts), reverse=True):
-            try:
-                directory.rmdir()
-            except OSError:
-                logger.warning(
-                    f"A directory '{directory}' is not empty after uninstallation of '{name}'. "
-                    "This might cause problems when installing a new version of the package. ",
-                )
-
-        if hasattr(loadedPackages, name):
-            delattr(loadedPackages, name)
-        else:
-            # This should not happen, but just in case
-            logger.warning(
-                f"a package '{name}' was not found in loadedPackages.",
-            )
-
-        logger.info(f"Successfully uninstalled {name}-{version}")
+    uninstall_distributions(distributions)
 
     importlib.invalidate_caches()

micropip/_uninstall.py

@@ -0,0 +1,78 @@
+import logging
+from collections.abc import Iterable
+from importlib.metadata import Distribution
+
+from ._compat import loadedPackages
+from ._utils import get_files_in_distribution, get_root
+
+logger = logging.getLogger("micropip")
+
+
+def uninstall_distributions(distributions: Iterable[Distribution]) -> None:
+    """Uninstall the given package distributions.
+
+    This function does not do any checks, so make sure that the distributions
+    are installed and that they are installed using a wheel file, i.e. packages
+    that have distribution metadata.
+
+    This function also does not invalidate the import cache, so make sure to
+    call `importlib.invalidate_caches()` after calling this function.
+
+    Parameters
+    ----------
+    distributions
+        Package distributions to uninstall.
+    """
+
+    for dist in distributions:
+        # Note: this value needs to be retrieved before removing files, as
+        #       dist.name uses metadata file to get the name
+        name = dist.name
+        version = dist.version
+
+        logger.info(f"Found existing installation: {name} {version}")
+
+        root = get_root(dist)
+        files = get_files_in_distribution(dist)
+        directories = set()
+
+        for file in files:
+            if not file.is_file():
+                if not file.is_relative_to(root):
+                    # This file is not in the site-packages directory. Probably one of:
+                    # - data_files
+                    # - scripts
+                    # - entry_points
+                    # Since we don't support these, we can ignore them (except for data_files (TODO))
+                    continue
+
+                logger.warning(
+                    f"A file '{file}' listed in the metadata of '{name}' does not exist.",
+                )
+
+                continue
+
+            file.unlink()
+
+            if file.parent != root:
+                directories.add(file.parent)
+
+        # Remove directories in reverse hierarchical order
+        for directory in sorted(directories, key=lambda x: len(x.parts), reverse=True):
+            try:
+                directory.rmdir()
+            except OSError:
+                logger.warning(
+                    f"A directory '{directory}' is not empty after uninstallation of '{name}'. "
+                    "This might cause problems when installing a new version of the package. ",
+                )
+
+        if hasattr(loadedPackages, name):
+            delattr(loadedPackages, name)
+        else:
+            # This should not happen, but just in case
+            logger.warning(
+                f"a package '{name}' was not found in loadedPackages.",
+            )
+
+        logger.info(f"Successfully uninstalled {name}-{version}")

micropip/transaction.py

@@ -233,6 +233,7 @@ class Transaction:
     keep_going: bool
     deps: bool
     pre: bool
+    reinstall: bool
     fetch_kwargs: dict[str, str]
 
     locked: dict[str, PackageMetadata] = field(default_factory=dict)
@@ -265,7 +266,21 @@ async def add_requirement(self, req: str | Requirement) -> None:
 
         await self.add_wheel(wheel, extras=set(), specifier="")
 
-    def check_version_satisfied(self, req: Requirement) -> tuple[bool, str]:
+    def check_version_satisfied(
+        self, req: Requirement, *, allow_reinstall: bool = False
+    ) -> tuple[bool, str]:
+        """
+        Check if the installed version of a package satisfies the requirement.
+        Returns True if the requirement is satisfied, False otherwise.
+
+        Parameters
+        ----------
+        req
+            The requirement to check.
+        allow_reinstall
+            If False, this function will raise exception if the package is already installed
+            and the installed version does not satisfy the requirement.
+        """
         ver = None
         try:
             ver = importlib.metadata.version(req.name)
@@ -281,9 +296,16 @@ def check_version_satisfied(self, req: Requirement) -> tuple[bool, str]:
             # installed version matches, nothing to do
             return True, ver
 
-        raise ValueError(
-            f"Requested '{req}', " f"but {req.name}=={ver} is already installed"
-        )
+        if allow_reinstall:
+            return False, ""
+        else:
+            raise ValueError(
+                f"Requested '{req}', "
+                f"but {req.name}=={ver} is already installed. "
+                "If you want to reinstall the package with a different version, "
+                "use micropip.install(..., reinstall=True) to force reinstall, "
+                "or micropip.uninstall(...) to uninstall the package first."
+            )
 
     async def add_requirement_inner(
         self,
@@ -336,7 +358,9 @@ def eval_marker(e: dict[str, str]) -> bool:
         # Is some version of this package is already installed?
         req.name = canonicalize_name(req.name)
 
-        satisfied, ver = self.check_version_satisfied(req)
+        satisfied, ver = self.check_version_satisfied(
+            req, allow_reinstall=self.reinstall
+        )
         if satisfied:
             logger.info(f"Requirement already satisfied: {req} ({ver})")
             return
@@ -363,10 +387,12 @@ def eval_marker(e: dict[str, str]) -> bool:
             else:
                 return
 
-        # Maybe while we were downloading pypi_json some other branch
-        # installed the wheel?
-        satisfied, ver = self.check_version_satisfied(req)
+        satisfied, ver = self.check_version_satisfied(
+            req, allow_reinstall=self.reinstall
+        )
         if satisfied:
+            # Maybe while we were downloading pypi_json some other branch
+            # installed the wheel?
             logger.info(f"Requirement already satisfied: {req} ({ver})")
             return
 

tests/conftest.py

@@ -108,10 +108,20 @@ def _mock_importlib_version(name: str) -> str:
     def _mock_importlib_distributions():
         return (Distribution.at(p) for p in wheel_base.glob("*.dist-info"))  # type: ignore[union-attr]
 
+    def _mock_importlib_distribution(name: str) -> Distribution:
+        for dist in _mock_importlib_distributions():
+            if dist.name == name:
+                return dist
+
+        raise PackageNotFoundError(name)
+
     monkeypatch.setattr(importlib.metadata, "version", _mock_importlib_version)
     monkeypatch.setattr(
         importlib.metadata, "distributions", _mock_importlib_distributions
     )
+    monkeypatch.setattr(
+        importlib.metadata, "distribution", _mock_importlib_distribution
+    )
 
 
 class Wildcard:

tests/test_install.py

@@ -363,6 +363,34 @@ async def run_test(selenium, url, wheel_name):
         run_test(selenium_standalone_micropip, url, SNOWBALL_WHEEL)
 
 
+@pytest.mark.asyncio
+async def test_reinstall_different_version(
+    mock_fetch: mock_fetch_cls,
+    mock_importlib,
+) -> None:
+    import importlib.metadata
+
+    import pytest
+
+    dummy = "dummy"
+    version_old = "1.0.0"
+    version_new = "2.0.0"
+
+    mock_fetch.add_pkg_version(dummy, version_old)
+    mock_fetch.add_pkg_version(dummy, version_new)
+
+    await micropip.install(f"{dummy}=={version_new}")
+    assert micropip.list()[dummy].version == version_new
+    assert importlib.metadata.version(dummy) == version_new
+
+    with pytest.raises(ValueError, match="already installed"):
+        await micropip.install(f"{dummy}=={version_old}", reinstall=False)
+
+    await micropip.install(f"{dummy}=={version_old}", reinstall=True)
+    assert micropip.list()[dummy].version == version_old
+    assert importlib.metadata.version(dummy) == version_old
+
+
 def test_logging(selenium_standalone_micropip):
     # TODO: make a fixture for this, it's used in a few places
     with spawn_web_server(Path(__file__).parent / "dist") as server:

tests/test_transaction.py

@@ -63,6 +63,7 @@ def create_transaction(Transaction):
         ctx={},
         ctx_extras=[],
         fetch_kwargs={},
+        reinstall=False,
     )