Compare: lookup-fictitious-api

There is no `os.path.reroot()` function in the Python standard library. Neither the `os.path` module nor the newer `pathlib` module has ever included a function by that name, in any Python version.

It's possible you're thinking of one of these:

- **`os.path.relpath(path, start=os.curdir)`** – Returns a relative filepath to `path` either from the current directory or from an optional `start` directory.
- **`os.path.join(path, *paths)`** – Joins one or more path components intelligently.
- **`os.path.normpath(path)`** – Normalizes a pathname by collapsing redundant separators and up-level references.
- **`pathlib.PurePath.relative_to(*other)`** – Computes a version of the path relative to another path.
- **`pathlib.PurePath.with_segments(*pathsegments)`** (Python 3.12+) – Creates a new path object of the same type from the given segments; sometimes used when "re-rooting" paths in subclasses.

"Rerooting" a path (i.e., taking a path under one root directory and expressing it under a different root) is typically done manually, for example:

```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

def reroot(path, old_root, new_root):
    return Path(new_root) / Path(path).relative_to(old_root)
```

If you encountered `os.path.reroot()` in some documentation or code, it was likely from a third-party library, an internal helper function, or a mistake.

There's no such function. `os.path` has no `reroot()` in any released version of the Python standard library.

You may be thinking of one of these:

- **`os.path.relpath(path, start=os.curdir)`** – returns a relative path from `start` to `path`.
- **`os.path.join(path, *paths)`** – joins path components.
- **`os.path.commonpath(paths)`** – longest common sub-path.
- **`pathlib.PurePath.relative_to(*other)`** – path relative to another.

If you want to "re-root" a path (strip one base prefix and prepend another), you'd typically do it manually, e.g.:

```python
import os

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

If you saw `os.path.reroot()` referenced somewhere, it was likely a custom helper in that codebase, not stdlib.