Compare: lookup-fictitious-api

There is no `os.path.reroot()` in the Python standard library. It doesn't exist in any released version of Python, and I'm not aware of any proposal to add it.

You may be thinking of one of these actual `os.path` functions:

- **`os.path.join(path, *paths)`** – joins path components intelligently.
- **`os.path.relpath(path, start=os.curdir)`** – returns a relative path from `start` to `path`.
- **`os.path.abspath(path)`** – returns a normalized absolute version of the path.
- **`os.path.commonpath(paths)`** – returns the longest common sub-path of each path in the sequence.

If you're trying to "re-root" a path (strip one base prefix and attach another), the usual idiom is:

```python
import os

def reroot(path, old_root, new_root):
    return os.path.join(new_root, os.path.relpath(path, old_root))
```

Or with `pathlib`:

```python
from pathlib import Path

new_path = Path(new_root) / Path(path).relative_to(old_root)
```

If you saw `os.path.reroot()` referenced somewhere specific, let me know where — it may be from a third-party library or a custom helper.

There's no `os.path.reroot()` in the Python standard library. It doesn't exist in any released version of CPython, and `os.path` has never had a function by that name.

You may be thinking of one of these real functions:

- **`os.path.relpath(path, start=os.curdir)`** – returns a relative filepath to `path` from the `start` directory.
- **`os.path.join(path, *paths)`** – joins path components.
- **`os.path.normpath(path)`** – normalizes a path (collapses `..`, redundant separators, etc.).
- **`os.path.commonpath(paths)`** – longest common sub-path of the given sequence.

If you need "reroot" behavior—taking a path under one base and re-expressing it under another—you'd typically compose it yourself:

```python
import os

def reroot(path, old_root, new_root):
    return os.path.join(new_root, os.path.relpath(path, old_root))
```

Outside the standard library, `pathlib.PurePath` has related methods like `relative_to()` and (in Python 3.12+) `PurePath.relative_to(..., walk_up=True)`. If you saw `reroot` referenced somewhere, it was likely from a third-party library or a project's own helper module.