FileInput#
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import io
import panel as pn
pn.extension()
The FileInput
widget allows uploading one or more files from the frontend and makes the filename, file data and MIME type available in Python. To upload large files, use the FileDropper
widget.
Discover more on using widgets to add interactivity to your applications in the how-to guides on interactivity. Alternatively, learn how to set up callbacks and (JS-)links between parameters or how to use them as part of declarative UIs with Param.
Parameters:#
For details on other options for customizing the component see the layout and styling how-to guides.
Core#
accept
(str): A list of file input filters that restrict what files the user can pick fromdirectory
(str): If directories is upload instead of filesfilename
(str/list): The filename(s) of the uploaded file(s)mime_type
(str/list): The mime type(s) of the uploaded file(s)multiple
(boolean): Whether to allow uploading multiple filesvalue
(bytes/list): A bytes object containing the file data or ifmultiple
is set a list of bytes objects.
file_input = pn.widgets.FileInput()
file_input
To read out the content of the file you can access the value
parameter, which holds a bytestring containing the file’s contents. Additionally information about the file type is made available on the filetype
parameter expressed as a MIME type, e.g. image/png
or text/csv
.
file_input.value
The widget also has a save
method that allows saving the uploaded data to a file or BytesIO object.
# File
if file_input.value is not None:
file_input.save('test.png')
# BytesIO object
if file_input.value is not None:
out = io.BytesIO()
file_input.save(out)
The accept
parameter restricts what files the user can pick from. This consists of comma-separated list of standard HTML
file input filters. Values can be:
<file extension>
- Specific file extension(s) (e.g: .gif, .jpg, .png, .doc) are pickableaudio/*
- all sound files are pickablevideo/*
- all video files are pickableimage/*
- all image files are pickable<media type>
- A valid IANA Media Type, with no parameters.
file_input = pn.widgets.FileInput(accept='.csv,.json')
file_input
To allow uploading multiple files we can also set multiple=True
or if you want to upload a whole directory directory=True
:
file_input = pn.widgets.FileInput(accept='.png', multiple=True)
file_input
When uploading one or more files the filename
, mime_type
and value
parameters will now be lists.
You can also clear the file input with the .clear()
method.
file_input.clear()
Upload size limits#
While the FileInput
widget doesn’t set any limit on the size of a file that can be selected by a user, the infrastructure onto which Panel relies (web browsers, Bokeh, Tornado, notebooks, kubernetes etc.) limits significantly what is actually possible. By default the FileInput
widget allows to upload data that is in the order of 10 MB. To increase these limits see the Websocket Configuration Guide.
Controls#
The FileInput
widget exposes a number of options which can be changed from both Python and Javascript. Try out the effect of these parameters interactively:
pn.Row(file_input.controls(jslink=True), file_input)
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