From 1aa718a4a731cf6b1a4b3b2d1aa81469718d4c69 Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Tue, 25 Apr 2023 05:00:09 +0000
Subject: [PATCH 01/10] Add force_reinstall option

---
 micropip/_commands/install.py   | 13 +++++++++++++
 micropip/_commands/uninstall.py | 14 ++++++++++----
 micropip/transaction.py         | 11 +++++++----
 3 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/micropip/_commands/install.py b/micropip/_commands/install.py
index 53fad75..f66ea77 100644
--- a/micropip/_commands/install.py
+++ b/micropip/_commands/install.py
@@ -7,6 +7,7 @@
 from .._compat import loadPackage, to_js
 from ..constants import FAQ_URLS
 from ..transaction import Transaction
+from .uninstall import uninstall
 
 
 async def install(
@@ -15,6 +16,7 @@ async def install(
     deps: bool = True,
     credentials: str | None = None,
     pre: bool = False,
+    force_reinstall: bool = False,
 ) -> None:
     """Install the given package and all of its dependencies.
 
@@ -83,6 +85,9 @@ async def install(
         If ``True``, include pre-release and development versions. By default,
         micropip only finds stable versions.
 
+    force_reinstall :
+
+        If ``True``, reinstall all packages even if they are already up-to-date.
     """
     ctx = default_environment()
     if isinstance(requirements, str):
@@ -106,6 +111,7 @@ async def install(
         keep_going=keep_going,
         deps=deps,
         pre=pre,
+        force_reinstall=force_reinstall,
         fetch_kwargs=fetch_kwargs,
     )
     await transaction.gather_requirements(requirements)
@@ -117,6 +123,13 @@ async def install(
             f"See: {FAQ_URLS['cant_find_wheel']}\n"
         )
 
+    # uninstall packages that are installed
+    uninstall_packages = set([pkg.name for pkg in transaction.wheels]) | set(
+        [pkg.name for pkg in transaction.pyodide_packages]
+    )
+
+    uninstall(uninstall_packages, _ignore_missing=True)
+
     wheel_promises = []
     # Install built-in packages
     pyodide_packages = transaction.pyodide_packages
diff --git a/micropip/_commands/uninstall.py b/micropip/_commands/uninstall.py
index 5a71469..032e0a7 100644
--- a/micropip/_commands/uninstall.py
+++ b/micropip/_commands/uninstall.py
@@ -1,13 +1,14 @@
 import importlib
 import importlib.metadata
 import warnings
+from collections.abc import Iterable
 from importlib.metadata import Distribution
 
 from .._compat import loadedPackages
 from .._utils import get_files_in_distribution, get_root
 
 
-def uninstall(packages: str | list[str]) -> None:
+def uninstall(packages: str | Iterable[str], *, _ignore_missing: bool = False) -> None:
     """Uninstall the given packages.
 
     This function only supports uninstalling packages that are installed
@@ -22,6 +23,9 @@ def uninstall(packages: str | list[str]) -> None:
     ----------
     packages
         Packages to uninstall.
+
+    _ignore_missing
+        If ``True``, suppress warnings when a package is not installed.
     """
 
     if isinstance(packages, str):
@@ -33,9 +37,11 @@ def uninstall(packages: str | list[str]) -> None:
             dist = importlib.metadata.distribution(package)
             distributions.append(dist)
         except importlib.metadata.PackageNotFoundError:
-            warnings.warn(
-                f"WARNING: Skipping '{package}' as it is not installed.", stacklevel=1
-            )
+            if not _ignore_missing:  # TODO: Can we utilize log level here?
+                warnings.warn(
+                    f"WARNING: Skipping '{package}' as it is not installed.",
+                    stacklevel=1,
+                )
 
     for dist in distributions:
         # Note: this value needs to be retrieved before removing files, as
diff --git a/micropip/transaction.py b/micropip/transaction.py
index 4fe6830..291cfd1 100644
--- a/micropip/transaction.py
+++ b/micropip/transaction.py
@@ -230,6 +230,7 @@ class Transaction:
     keep_going: bool
     deps: bool
     pre: bool
+    force_reinstall: bool
     fetch_kwargs: dict[str, str]
 
     locked: dict[str, PackageMetadata] = field(default_factory=dict)
@@ -261,6 +262,10 @@ async def add_requirement(self, req: str | Requirement) -> None:
         await self.add_wheel(wheel, extras=set())
 
     def check_version_satisfied(self, req: Requirement) -> bool:
+        """
+        Check if the installed version of a package satisfies the requirement.
+        Returns True if the requirement is satisfied, False otherwise.
+        """
         ver = None
         try:
             ver = importlib.metadata.version(req.name)
@@ -276,9 +281,7 @@ def check_version_satisfied(self, req: Requirement) -> bool:
             # installed version matches, nothing to do
             return True
 
-        raise ValueError(
-            f"Requested '{req}', " f"but {req.name}=={ver} is already installed"
-        )
+        return False
 
     async def add_requirement_inner(
         self,
@@ -330,7 +333,7 @@ def eval_marker(e: dict[str, str]) -> bool:
                 return
         # Is some version of this package is already installed?
         req.name = canonicalize_name(req.name)
-        if self.check_version_satisfied(req):
+        if not self.force_reinstall and self.check_version_satisfied(req):
             return
 
         # If there's a Pyodide package that matches the version constraint, use

From 85e24155a9166bf0db24a8cc118c97af534e79f3 Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Tue, 25 Apr 2023 05:27:22 +0000
Subject: [PATCH 02/10] Add tests

---
 micropip/_commands/install.py   |  4 +--
 micropip/_commands/uninstall.py |  4 +--
 micropip/transaction.py         |  2 +-
 tests/conftest.py               | 10 ++++++
 tests/test_install.py           | 59 +++++++++++++++++++++++++++++++++
 tests/test_transaction.py       |  1 +
 6 files changed, 75 insertions(+), 5 deletions(-)

diff --git a/micropip/_commands/install.py b/micropip/_commands/install.py
index f66ea77..ed405f8 100644
--- a/micropip/_commands/install.py
+++ b/micropip/_commands/install.py
@@ -124,11 +124,11 @@ async def install(
         )
 
     # uninstall packages that are installed
-    uninstall_packages = set([pkg.name for pkg in transaction.wheels]) | set(
+    packages_all = set([pkg.name for pkg in transaction.wheels]) | set(
         [pkg.name for pkg in transaction.pyodide_packages]
     )
 
-    uninstall(uninstall_packages, _ignore_missing=True)
+    uninstall(packages_all, ignore_missing=True)
 
     wheel_promises = []
     # Install built-in packages
diff --git a/micropip/_commands/uninstall.py b/micropip/_commands/uninstall.py
index 032e0a7..46f52ae 100644
--- a/micropip/_commands/uninstall.py
+++ b/micropip/_commands/uninstall.py
@@ -8,7 +8,7 @@
 from .._utils import get_files_in_distribution, get_root
 
 
-def uninstall(packages: str | Iterable[str], *, _ignore_missing: bool = False) -> None:
+def uninstall(packages: str | Iterable[str], *, ignore_missing: bool = False) -> None:
     """Uninstall the given packages.
 
     This function only supports uninstalling packages that are installed
@@ -37,7 +37,7 @@ def uninstall(packages: str | Iterable[str], *, _ignore_missing: bool = False) -
             dist = importlib.metadata.distribution(package)
             distributions.append(dist)
         except importlib.metadata.PackageNotFoundError:
-            if not _ignore_missing:  # TODO: Can we utilize log level here?
+            if not ignore_missing:  # TODO: Can we utilize log level here?
                 warnings.warn(
                     f"WARNING: Skipping '{package}' as it is not installed.",
                     stacklevel=1,
diff --git a/micropip/transaction.py b/micropip/transaction.py
index 291cfd1..c4c218d 100644
--- a/micropip/transaction.py
+++ b/micropip/transaction.py
@@ -358,7 +358,7 @@ def eval_marker(e: dict[str, str]) -> bool:
             else:
                 return
 
-        if self.check_version_satisfied(req):
+        if not self.force_reinstall and self.check_version_satisfied(req):
             # Maybe while we were downloading pypi_json some other branch
             # installed the wheel?
             return
diff --git a/tests/conftest.py b/tests/conftest.py
index 64e661c..f427067 100644
--- a/tests/conftest.py
+++ b/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:
diff --git a/tests/test_install.py b/tests/test_install.py
index 61818ff..e15fb17 100644
--- a/tests/test_install.py
+++ b/tests/test_install.py
@@ -360,3 +360,62 @@ 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
+
+    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_old}")
+    assert micropip.list()[dummy].version == version_old
+    assert importlib.metadata.version(dummy) == version_old
+
+    await micropip.install(f"{dummy}=={version_new}")
+    assert micropip.list()[dummy].version == version_new
+    assert importlib.metadata.version(dummy) == version_new
+
+    await micropip.install(f"{dummy}=={version_old}")
+    assert micropip.list()[dummy].version == version_old
+    assert importlib.metadata.version(dummy) == version_old
+
+
+@pytest.mark.asyncio
+async def test_force_reinstall(
+    mock_fetch: mock_fetch_cls,
+    mock_importlib,
+) -> None:
+    import importlib.metadata
+
+    dummy = "dummy"
+    version_old = "1.0.0"
+
+    mock_fetch.add_pkg_version(dummy, version_old)
+
+    await micropip.install(f"{dummy}=={version_old}")
+    assert micropip.list()[dummy].version == version_old
+    assert importlib.metadata.version(dummy) == version_old
+
+    dist_path = importlib.metadata.distribution(dummy)._path  # type: ignore[attr-defined]
+    assert dist_path.exists()
+
+    # create a dummy file in the dist_info directory, then force reinstall
+    # the package. The dummy file should be removed.
+    dummy_file = dist_path / "dummy"
+    dummy_file.touch()
+    assert dummy_file.exists()
+
+    await micropip.install(f"{dummy}=={version_old}", force_reinstall=True)
+    assert micropip.list()[dummy].version == version_old
+    assert importlib.metadata.version(dummy) == version_old
+
+    assert not dummy_file.exists()
diff --git a/tests/test_transaction.py b/tests/test_transaction.py
index 4a67238..05aa559 100644
--- a/tests/test_transaction.py
+++ b/tests/test_transaction.py
@@ -63,6 +63,7 @@ def create_transaction(Transaction):
         ctx={},
         ctx_extras=[],
         fetch_kwargs={},
+        force_reinstall=False,
     )
 
 

From 4068fe2aa3457da3079cc4eb1008c889dea29ecf Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Tue, 25 Apr 2023 09:49:29 +0000
Subject: [PATCH 03/10] Some refactorings

---
 micropip/_commands/install.py   | 11 ++++-
 micropip/_commands/uninstall.py | 64 +++------------------------
 micropip/_uninstall.py          | 78 +++++++++++++++++++++++++++++++++
 3 files changed, 92 insertions(+), 61 deletions(-)
 create mode 100644 micropip/_uninstall.py

diff --git a/micropip/_commands/install.py b/micropip/_commands/install.py
index ed405f8..284e8eb 100644
--- a/micropip/_commands/install.py
+++ b/micropip/_commands/install.py
@@ -5,9 +5,9 @@
 from packaging.markers import default_environment
 
 from .._compat import loadPackage, to_js
+from .._uninstall import _uninstall
 from ..constants import FAQ_URLS
 from ..transaction import Transaction
-from .uninstall import uninstall
 
 
 async def install(
@@ -128,7 +128,14 @@ async def install(
         [pkg.name for pkg in transaction.pyodide_packages]
     )
 
-    uninstall(packages_all, ignore_missing=True)
+    distributions = []
+    for pkg_name in packages_all:
+        try:
+            distributions.append(importlib.metadata.distribution(pkg_name))
+        except importlib.metadata.PackageNotFoundError:
+            pass
+
+    _uninstall(distributions)
 
     wheel_promises = []
     # Install built-in packages
diff --git a/micropip/_commands/uninstall.py b/micropip/_commands/uninstall.py
index 46f52ae..220e1ca 100644
--- a/micropip/_commands/uninstall.py
+++ b/micropip/_commands/uninstall.py
@@ -4,11 +4,10 @@
 from collections.abc import Iterable
 from importlib.metadata import Distribution
 
-from .._compat import loadedPackages
-from .._utils import get_files_in_distribution, get_root
+from .._uninstall import _uninstall
 
 
-def uninstall(packages: str | Iterable[str], *, ignore_missing: bool = False) -> None:
+def uninstall(packages: str | Iterable[str]) -> None:
     """Uninstall the given packages.
 
     This function only supports uninstalling packages that are installed
@@ -23,9 +22,6 @@ def uninstall(packages: str | Iterable[str], *, ignore_missing: bool = False) ->
     ----------
     packages
         Packages to uninstall.
-
-    _ignore_missing
-        If ``True``, suppress warnings when a package is not installed.
     """
 
     if isinstance(packages, str):
@@ -37,61 +33,11 @@ def uninstall(packages: str | Iterable[str], *, ignore_missing: bool = False) ->
             dist = importlib.metadata.distribution(package)
             distributions.append(dist)
         except importlib.metadata.PackageNotFoundError:
-            if not ignore_missing:  # TODO: Can we utilize log level here?
-                warnings.warn(
-                    f"WARNING: Skipping '{package}' as it is not installed.",
-                    stacklevel=1,
-                )
-
-    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
-
-        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
-
-                warnings.warn(
-                    f"WARNING: A file '{file}' listed in the metadata of '{dist.name}' does not exist.",
-                    stacklevel=1,
-                )
-
-                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:
-                warnings.warn(
-                    f"WARNING: A directory '{directory}' is not empty after uninstallation of '{name}'. "
-                    "This might cause problems when installing a new version of the package. ",
-                    stacklevel=1,
-                )
-
-        if hasattr(loadedPackages, name):
-            delattr(loadedPackages, name)
-        else:
-            # This should not happen, but just in case
             warnings.warn(
-                f"WARNING: a package '{name}' was not found in loadedPackages.",
+                f"WARNING: Skipping '{package}' as it is not installed.",
                 stacklevel=1,
             )
 
+    _uninstall(distributions)
+
     importlib.invalidate_caches()
diff --git a/micropip/_uninstall.py b/micropip/_uninstall.py
new file mode 100644
index 0000000..d2427af
--- /dev/null
+++ b/micropip/_uninstall.py
@@ -0,0 +1,78 @@
+import importlib
+import importlib.metadata
+import warnings
+from collections.abc import Iterable
+from importlib.metadata import Distribution
+
+from ._compat import loadedPackages
+from ._utils import get_files_in_distribution, get_root
+
+
+def _uninstall(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
+
+        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
+
+                warnings.warn(
+                    f"WARNING: A file '{file}' listed in the metadata of '{dist.name}' does not exist.",
+                    stacklevel=1,
+                )
+
+                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:
+                warnings.warn(
+                    f"WARNING: A directory '{directory}' is not empty after uninstallation of '{name}'. "
+                    "This might cause problems when installing a new version of the package. ",
+                    stacklevel=1,
+                )
+
+        if hasattr(loadedPackages, name):
+            delattr(loadedPackages, name)
+        else:
+            # This should not happen, but just in case
+            warnings.warn(
+                f"WARNING: a package '{name}' was not found in loadedPackages.",
+                stacklevel=1,
+            )
+
+    importlib.invalidate_caches()

From 35fc850e5bde1ac36290c9e032a32d6ce0542334 Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Tue, 25 Apr 2023 10:09:58 +0000
Subject: [PATCH 04/10] Rename internal method

---
 micropip/_commands/install.py   | 4 ++--
 micropip/_commands/uninstall.py | 4 ++--
 micropip/_uninstall.py          | 6 +-----
 3 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/micropip/_commands/install.py b/micropip/_commands/install.py
index 284e8eb..b9e251d 100644
--- a/micropip/_commands/install.py
+++ b/micropip/_commands/install.py
@@ -5,7 +5,7 @@
 from packaging.markers import default_environment
 
 from .._compat import loadPackage, to_js
-from .._uninstall import _uninstall
+from .._uninstall import uninstall_distributions
 from ..constants import FAQ_URLS
 from ..transaction import Transaction
 
@@ -135,7 +135,7 @@ async def install(
         except importlib.metadata.PackageNotFoundError:
             pass
 
-    _uninstall(distributions)
+    uninstall_distributions(distributions)
 
     wheel_promises = []
     # Install built-in packages
diff --git a/micropip/_commands/uninstall.py b/micropip/_commands/uninstall.py
index 220e1ca..a8a7ca9 100644
--- a/micropip/_commands/uninstall.py
+++ b/micropip/_commands/uninstall.py
@@ -4,7 +4,7 @@
 from collections.abc import Iterable
 from importlib.metadata import Distribution
 
-from .._uninstall import _uninstall
+from .._uninstall import uninstall_distributions
 
 
 def uninstall(packages: str | Iterable[str]) -> None:
@@ -38,6 +38,6 @@ def uninstall(packages: str | Iterable[str]) -> None:
                 stacklevel=1,
             )
 
-    _uninstall(distributions)
+    uninstall_distributions(distributions)
 
     importlib.invalidate_caches()
diff --git a/micropip/_uninstall.py b/micropip/_uninstall.py
index d2427af..7431c8a 100644
--- a/micropip/_uninstall.py
+++ b/micropip/_uninstall.py
@@ -1,5 +1,3 @@
-import importlib
-import importlib.metadata
 import warnings
 from collections.abc import Iterable
 from importlib.metadata import Distribution
@@ -8,7 +6,7 @@
 from ._utils import get_files_in_distribution, get_root
 
 
-def _uninstall(distributions: Iterable[Distribution]) -> None:
+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
@@ -74,5 +72,3 @@ def _uninstall(distributions: Iterable[Distribution]) -> None:
                 f"WARNING: a package '{name}' was not found in loadedPackages.",
                 stacklevel=1,
             )
-
-    importlib.invalidate_caches()

From 7ad86b7a675ef9040e034f924865136047f5a22d Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Thu, 4 May 2023 06:17:01 +0000
Subject: [PATCH 05/10] Rename force_reinstall to reinstall

---
 micropip/_commands/install.py |  8 ++++----
 micropip/transaction.py       | 38 +++++++++++++++++++++++++++--------
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/micropip/_commands/install.py b/micropip/_commands/install.py
index 9811d48..1e8a6f9 100644
--- a/micropip/_commands/install.py
+++ b/micropip/_commands/install.py
@@ -17,7 +17,7 @@ async def install(
     deps: bool = True,
     credentials: str | None = None,
     pre: bool = False,
-    force_reinstall: bool = False,
+    reinstall: bool = False,
     *,
     verbose: bool | int = False,
 ) -> None:
@@ -88,9 +88,9 @@ async def install(
         If ``True``, include pre-release and development versions. By default,
         micropip only finds stable versions.
 
-    force_reinstall :
+    reinstall :
 
-        If ``True``, reinstall all packages even if they are already up-to-date.
+        If ``True``, reinstall packages if they are already installed.
 
     verbose :
         Print more information about the process.
@@ -121,7 +121,7 @@ async def install(
         keep_going=keep_going,
         deps=deps,
         pre=pre,
-        force_reinstall=force_reinstall,
+        reinstall=reinstall,
         fetch_kwargs=fetch_kwargs,
         verbose=verbose,
     )
diff --git a/micropip/transaction.py b/micropip/transaction.py
index adfaccd..4cecaa1 100644
--- a/micropip/transaction.py
+++ b/micropip/transaction.py
@@ -233,7 +233,7 @@ class Transaction:
     keep_going: bool
     deps: bool
     pre: bool
-    force_reinstall: bool
+    reinstall: bool
     fetch_kwargs: dict[str, str]
 
     locked: dict[str, PackageMetadata] = field(default_factory=dict)
@@ -266,10 +266,20 @@ 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:
@@ -286,7 +296,16 @@ def check_version_satisfied(self, req: Requirement) -> tuple[bool, str]:
             # installed version matches, nothing to do
             return True, ver
 
-        return False, ""
+        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,
@@ -339,9 +358,10 @@ 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)
-
-        if not self.force_reinstall and satisfied:
+        satisfied, ver = self.check_version_satisfied(
+            req, allow_reinstall=self.reinstall
+        )
+        if satisfied:
             logger.info(f"Requirement already satisfied: {req} ({ver})")
             return
 
@@ -367,8 +387,10 @@ def eval_marker(e: dict[str, str]) -> bool:
             else:
                 return
 
-        satisfied, ver = self.check_version_satisfied(req)
-        if not self.force_reinstall and satisfied:
+        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})")

From 03a902bd73ac0414ba79e2633db6cf6abbd60b98 Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Thu, 4 May 2023 06:18:55 +0000
Subject: [PATCH 06/10] Update test

---
 tests/test_install.py | 37 +++++--------------------------------
 1 file changed, 5 insertions(+), 32 deletions(-)

diff --git a/tests/test_install.py b/tests/test_install.py
index 2770af7..a46378f 100644
--- a/tests/test_install.py
+++ b/tests/test_install.py
@@ -370,6 +370,8 @@ async def test_reinstall_different_version(
 ) -> None:
     import importlib.metadata
 
+    import pytest
+
     dummy = "dummy"
     version_old = "1.0.0"
     version_new = "2.0.0"
@@ -385,42 +387,13 @@ async def test_reinstall_different_version(
     assert micropip.list()[dummy].version == version_new
     assert importlib.metadata.version(dummy) == version_new
 
-    await micropip.install(f"{dummy}=={version_old}")
-    assert micropip.list()[dummy].version == version_old
-    assert importlib.metadata.version(dummy) == version_old
-
-
-@pytest.mark.asyncio
-async def test_force_reinstall(
-    mock_fetch: mock_fetch_cls,
-    mock_importlib,
-) -> None:
-    import importlib.metadata
+    with pytest.raises(ValueError, match="already installed"):
+        await micropip.install(f"{dummy}=={version_old}", reinstall=False)
 
-    dummy = "dummy"
-    version_old = "1.0.0"
-
-    mock_fetch.add_pkg_version(dummy, version_old)
-
-    await micropip.install(f"{dummy}=={version_old}")
+    await micropip.install(f"{dummy}=={version_old}", reinstall=False)
     assert micropip.list()[dummy].version == version_old
     assert importlib.metadata.version(dummy) == version_old
 
-    dist_path = importlib.metadata.distribution(dummy)._path  # type: ignore[attr-defined]
-    assert dist_path.exists()
-
-    # create a dummy file in the dist_info directory, then force reinstall
-    # the package. The dummy file should be removed.
-    dummy_file = dist_path / "dummy"
-    dummy_file.touch()
-    assert dummy_file.exists()
-
-    await micropip.install(f"{dummy}=={version_old}", force_reinstall=True)
-    assert micropip.list()[dummy].version == version_old
-    assert importlib.metadata.version(dummy) == version_old
-
-    assert not dummy_file.exists()
-
 
 def test_logging(selenium_standalone_micropip):
     # TODO: make a fixture for this, it's used in a few places

From bdac07fe0b032035130fb75e1b375304955e8ceb Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Thu, 4 May 2023 06:20:07 +0000
Subject: [PATCH 07/10] Indent log

---
 micropip/_commands/install.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/micropip/_commands/install.py b/micropip/_commands/install.py
index 1e8a6f9..3a8bf1b 100644
--- a/micropip/_commands/install.py
+++ b/micropip/_commands/install.py
@@ -7,7 +7,7 @@
 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
 
 
@@ -146,7 +146,8 @@ async def install(
         except importlib.metadata.PackageNotFoundError:
             pass
 
-    uninstall_distributions(distributions)
+    with indent_log():
+        uninstall_distributions(distributions)
 
     if packages_all:
         logger.info("Installing collected packages: " + ", ".join(packages_all))

From a0196c38ca687272603bdb09e0af9713c9652c4e Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Thu, 4 May 2023 06:25:26 +0000
Subject: [PATCH 08/10] Fix tests

---
 tests/test_install.py     | 2 +-
 tests/test_transaction.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/test_install.py b/tests/test_install.py
index a46378f..e7f5b67 100644
--- a/tests/test_install.py
+++ b/tests/test_install.py
@@ -390,7 +390,7 @@ async def test_reinstall_different_version(
     with pytest.raises(ValueError, match="already installed"):
         await micropip.install(f"{dummy}=={version_old}", reinstall=False)
 
-    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
 
diff --git a/tests/test_transaction.py b/tests/test_transaction.py
index a40709a..65d368c 100644
--- a/tests/test_transaction.py
+++ b/tests/test_transaction.py
@@ -63,7 +63,7 @@ def create_transaction(Transaction):
         ctx={},
         ctx_extras=[],
         fetch_kwargs={},
-        force_reinstall=False,
+        reinstall=False,
     )
 
 

From f688b0ec5df157d693fcfa211020022889e5572f Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Mon, 8 May 2023 07:22:46 +0000
Subject: [PATCH 09/10] Fix test

---
 tests/test_install.py | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/tests/test_install.py b/tests/test_install.py
index e7f5b67..934faa1 100644
--- a/tests/test_install.py
+++ b/tests/test_install.py
@@ -379,10 +379,6 @@ async def test_reinstall_different_version(
     mock_fetch.add_pkg_version(dummy, version_old)
     mock_fetch.add_pkg_version(dummy, version_new)
 
-    await micropip.install(f"{dummy}=={version_old}")
-    assert micropip.list()[dummy].version == version_old
-    assert importlib.metadata.version(dummy) == version_old
-
     await micropip.install(f"{dummy}=={version_new}")
     assert micropip.list()[dummy].version == version_new
     assert importlib.metadata.version(dummy) == version_new

From 211559b09f9a2d29d1a7887ef4887eb2ec109e52 Mon Sep 17 00:00:00 2001
From: ryanking13 <def6488@gmail.com>
Date: Mon, 8 May 2023 07:24:16 +0000
Subject: [PATCH 10/10] Update changelog

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index efe35a4..465de4b 100644
--- a/CHANGELOG.md
+++ b/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