title: build_url
---
module: lektor.utils
---
signature: pieces, trailing_slash=None
---
summary: Helper function that assists in building URL paths.
---
type: function
---
version_added: 2.0
---
body:

This function assists in creating URL paths from individual segments.  This
is particularly useful for building virtual source objects.  It takes a bunch
of path segments and returns an absolute path.  The default behavior is to
guess the trailing slash based on the presence of a dot in the last path
segment.  If you want to override the detection you can explicitly pass
`True` to enforce a trailing slash or `False` to avoid it.

## Example

```pycon
>>> from lektor.utils import build_url
>>> build_url(['foo', 42])
u'/foo/42/'
>>> build_url(['foo', None, 23])
u'/foo/23/'
>>> build_url(['foo', 'hello.html'])
u'/foo/hello.html'
```