> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pixeltable.com/llms.txt
> Use this file to discover all available pages before exploring further.
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# Split data into multiple rows with iterators
This documentation page is also available as an interactive notebook. You can launch the notebook in
Kaggle or Colab, or download it for use with an IDE or local Jupyter installation, by clicking one of the
above links.
export const quartoRawHtml = [`
text
FINANCIAL SONAR™: REALITY RADAR ON COMPANY PERFORMANCE NASDAQGSAMZN
AMAZON.COM
INC. REGION NORTH AMERICA INDUSTRY INTERNET AND DIRECT MARKETING
RETAIL SELL OVERALL RATING FOR 1ST QUARTER 2024
www.jeffersonresearch.com
This makes development faster and more maintainable.
`, `
tile_coord
tile
[14, 0]
[1, 7]
[19, 7]
[1, 1]
`, `
segment_start
segment_end
0.
29.989
28.003
57.992
56.007
85.995
84.01
113.998
112.013
141.976
`];
Transform a single document, video, image, or audio file into multiple
rows for granular processing.
**What’s in this recipe:**
* Split documents into text chunks for RAG
* Extract frames or segments from videos
* Tile images for high-resolution analysis
* Chunk audio files for transcription
## Problem
You have documents, videos, or text that you need to break into smaller
pieces for processing. A PDF needs to be split into chunks for
retrieval-augmented generation. A video needs individual frames for
analysis. Text needs to be divided into sentences or sliding windows.
You need a way to transform one source row into multiple output rows
automatically.
## Solution
You create views with iterator functions that split source data into
multiple rows. Pixeltable provides built-in iterators for documents,
videos, images, audio, and strings.
### Setup
```python theme={null}
%pip install -qU pixeltable spacy tiktoken
!python -m spacy download en_core_web_sm -q
```
```python theme={null}
import pixeltable as pxt
```
### Split documents into chunks
Use `document_splitter` to break documents (PDF, HTML, Markdown, TXT)
into text chunks.
```python theme={null}
from pixeltable.functions.document import document_splitter
pxt.drop_dir('split_demo', force=True)
pxt.create_dir('split_demo')
docs = pxt.create_table('split_demo/docs', {'doc': pxt.Document})
docs.insert(
[
{
'doc': 'https://raw.githubusercontent.com/pixeltable/pixeltable/main/docs/resources/rag-demo/Jefferson-Amazon.pdf'
}
]
)
```
Inserted 1 row with 0 errors in 0.13 s (7.68 rows/s)
1 row inserted.
```python theme={null}
chunks = pxt.create_view(
'split_demo/doc_chunks',
docs,
iterator=document_splitter(
docs.doc, separators='sentence,token_limit', limit=300
),
)
chunks.select(chunks.text).limit(3).collect()
```
**Available separators:**
* `heading` — Split on HTML/Markdown headings
* `sentence` — Split on sentence boundaries (requires spacy)
* `token_limit` — Split by token count (requires tiktoken)
* `char_limit` — Split by character count
* `page` — Split by page (PDF only)
[SDK Reference:
document\_splitter](/sdk/latest/document)
### Extract frames from videos
Use `frame_iterator` to extract frames at specified intervals.
```python theme={null}
from pixeltable.functions.video import frame_iterator
videos = pxt.create_table('split_demo/videos', {'video': pxt.Video})
videos.insert(
[
{
'video': 'https://github.com/pixeltable/pixeltable/raw/main/docs/resources/bangkok.mp4'
}
]
)
```
Inserted 1 row with 0 errors in 1.28 s (0.78 rows/s)
1 row inserted.
```python theme={null}
frames = pxt.create_view(
'split_demo/frames',
videos,
iterator=frame_iterator(videos.video, fps=1.0),
)
frames.select(frames.frame, frames.frame_attrs).limit(3).collect()
```
**frame\_iterator options:**
* `fps` — Frames per second to extract
* `num_frames` — Extract exact number of frames (evenly spaced)
* `keyframes_only` — Extract only keyframes
[SDK Reference:
frame\_iterator](/sdk/latest/video)
### Split videos into segments
Use `video_splitter` to divide videos into smaller clips.
```python theme={null}
from pixeltable.functions.video import video_splitter
segments = pxt.create_view(
'split_demo/segments',
videos,
iterator=video_splitter(
videos.video, duration=5.0, min_segment_duration=1.0
),
)
segments.select(
segments.segment_start, segments.segment_end, segments.video_segment
).limit(3).collect()
```
**video\_splitter options:**
* `duration` — Duration of each segment in seconds
* `overlap` — Overlap between segments in seconds
* `min_segment_duration` — Drop last segment if shorter than this
[SDK Reference:
video\_splitter](/sdk/latest/video)
### Split strings into sentences
Use `string_splitter` to divide text into sentences.
```python theme={null}
from pixeltable.functions.string import string_splitter
texts = pxt.create_table('split_demo/texts', {'content': pxt.String})
texts.insert(
[
{
'content': 'AI data infrastructure simplifies ML workflows. Declarative pipelines update incrementally. This makes development faster and more maintainable.'
}
]
)
```
Inserted 1 row with 0 errors in 0.03 s (38.38 rows/s)
1 row inserted.
```python theme={null}
sentences = pxt.create_view(
'split_demo/sentences',
texts,
iterator=string_splitter(texts.content, separators='sentence'),
)
sentences.select(sentences.text).collect()
```
[SDK Reference:
string\_splitter](/sdk/latest/string)
### Tile images for analysis
Use `tile_iterator` to divide large images into a grid of smaller tiles.
This is useful for processing high-resolution images that are too large
to analyze at once, or for running object detection on different
regions.
```python theme={null}
from pixeltable.functions.image import tile_iterator
images = pxt.create_table('split_demo/images', {'image': pxt.Image})
images.insert(
[
{
'image': 'https://raw.githubusercontent.com/pixeltable/pixeltable/main/docs/resources/pixeltable-logo-large.png'
}
]
)
```
Inserted 1 row with 0 errors in 0.09 s (11.69 rows/s)
1 row inserted.
```python theme={null}
tiles = pxt.create_view(
'split_demo/tiles',
images,
iterator=tile_iterator(images.image, tile_size=(100, 100)),
)
```
**tile\_iterator options:**
* `tile_size` — Size of each tile as `(width, height)`
* `overlap` — Overlap between adjacent tiles as `(width, height)`
[SDK Reference:
tile\_iterator](/sdk/latest/image)
```python theme={null}
tiles.select(tiles.tile_coord, tiles.tile).sample(n=4).collect()
```
### Split audio into chunks
Use `audio_splitter` to divide audio files into time-based segments for
transcription or analysis.
```python theme={null}
from pixeltable.functions.audio import audio_splitter
audio = pxt.create_table('split_demo/audio', {'audio': pxt.Audio})
audio.insert(
[
{
'audio': 'https://raw.githubusercontent.com/pixeltable/pixeltable/main/docs/resources/10-minute%20tour%20of%20Pixeltable.mp3'
}
]
)
```
Inserted 1 row with 0 errors in 0.67 s (1.50 rows/s)
1 row inserted.
```python theme={null}
audio_segments = pxt.create_view(
'split_demo/audio_chunks',
audio,
iterator=audio_splitter(audio.audio, duration=30.0, overlap=2.0),
)
audio_segments.select(
audio_segments.segment_start, audio_segments.segment_end
).limit(5).collect()
```
**audio\_splitter options:**
* `duration` — Duration of each chunk in seconds
* `overlap` — Overlap between chunks in seconds
* `min_segment_duration` — Drop last chunk if shorter than this
[SDK Reference:
audio\_splitter](/sdk/latest/audio)
## See also
* [Split documents for
RAG](/howto/cookbooks/text/doc-chunk-for-rag)
* [Extract frames from
videos](/howto/cookbooks/video/video-extract-frames)
* [Transcribe audio
files](/howto/cookbooks/audio/audio-transcribe)
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