## get_content_type()


Return the most specific, commonly accepted MIME type for a filename or extension.


Usage

``` python
get_content_type(
    filename_or_extension,
    treat_as_binary=True,
    fallback=_UNSET,
)
```


The lookup is based purely on the extension -- the file's bytes are never read. A filename, a bare extension (with or without a leading dot), or a `pathlib.Path` are all accepted. For URLs, any query string (`?...`) or fragment (`#...`) is stripped first; for compound extensions the last segment wins (`archive.tar.gz` resolves as `gz`). Matching is case-insensitive.


## Parameters


`filename_or_extension: str | Path`  
A filename, path, URL, or bare extension to look up. Accepts a `str` or a `pathlib.Path`.

`treat_as_binary: bool = ``True`  
Selects the default fallback when the extension is unknown and no explicit `fallback` is given. `True` (default) returns `application/octet-stream`; `False` returns `text/plain`.

`fallback: Optional[str] | _Unset = _UNSET`    
An explicit value to return for unknown extensions. When provided, it takes precedence over `treat_as_binary`. Pass a MIME type string to override the default, or `None` to get `None` back for unknowns (handy when you want to branch on a miss rather than receive a placeholder type). When omitted entirely, the `treat_as_binary` default is used -- so existing callers are unaffected.


## Returns


`Optional[str]`  
For a known extension, its MIME type; otherwise the explicit `fallback` (which may be `None`) or the default.


## Raises


`TypeError`  
If `filename_or_extension` is `None`.


## Example

``` python
>>> get_content_type("picture.jpg")
'image/jpeg'
>>> get_content_type(".webp")
'image/webp'
>>> get_content_type("script.js")
'text/javascript'
>>> get_content_type("unknown.xyz")
'application/octet-stream'
>>> get_content_type("unknown.xyz", treat_as_binary=False)
'text/plain'
>>> get_content_type("unknown.xyz", fallback='application/x-custom')
'application/x-custom'
>>> get_content_type("unknown.xyz", fallback=None) is None
True
```