Working with Data in Pixeltable

Pixeltable provides a unified interface for working with diverse data types - from structured tables to unstructured media files. This guide covers everything you need to know about bringing your data into Pixeltable.

Supported Data Types & Formats

Basic Types (Int, Float, Bool, String, Timestamp)

import pixeltable as pxt
from datetime import datetime

# Create table with basic data types
basic_table = pxt.create_table('myproject.basic_types', {
    'id': pxt.Int,                  # Integer values
    'score': pxt.Float,             # Floating point numbers  
    'active': pxt.Bool,             # Boolean values
    'name': pxt.String,             # Text data
    'created_at': pxt.Timestamp     # DateTime values
})

# Insert single row
basic_table.insert([
    {
        'id': 1,
        'score': 95.5,
        'active': True,
        'name': 'Example',
        'created_at': datetime.now()
    }
])

# Batch insert
basic_table.insert([
    {
        'id': 2,
        'score': 88.3,
        'active': True,
        'name': 'Test A',
        'created_at': datetime(2024, 1, 1)
    },
    {
        'id': 3, 
        'score': 76.9,
        'active': False,
        'name': 'Test B',
        'created_at': datetime(2024, 1, 15)
    }
])

# Import from CSV
pxt.io.import_csv('myproject.from_csv', 'data.csv', 
    schema_overrides={
        'id': pxt.Int,
        'score': pxt.Float,
        'active': pxt.Bool,
        'created_at': pxt.Timestamp
    }
)

# Import from Excel
pxt.io.import_excel('myproject.from_excel', 'data.xlsx',
    schema_overrides={
        'id': pxt.Int,
        'score': pxt.Float,
        'active': pxt.Bool,
        'created_at': pxt.Timestamp
    }
)

Array Type

# Create table with array columns
array_table = pxt.create_table('myproject.arrays', {
    'fixed_vector': pxt.Array[(768,), pxt.Float],      # Fixed-size vector
    'variable_tensor': pxt.Array[(None, 512), pxt.Float], # Variable first dimension
    'any_int_array': pxt.Array[pxt.Int],               # Any-shaped integer array
    'any_float_array': pxt.Array[pxt.Float],           # Any-shaped float array
    'completely_flexible': pxt.Array                    # Any array (shape and dtype)
})

# Insert array data
array_table.insert([{
    'fixed_vector': np.random.randn(768),
    'variable_tensor': np.random.randn(5, 512),
    'any_int_array': np.array([1, 2, 3, 4]),          # 1D array
    'any_float_array': np.random.randn(3, 3),         # 2D array
    'completely_flexible': np.array([[1, 2], [3, 4]])  # Any numpy array
}])

JSON Type

# Create table with JSON columns
json_table = pxt.create_table('myproject.json_data', {
    'metadata': pxt.Json,           # Arbitrary JSON data
    'config': pxt.Json,             # Configuration objects
    'features': pxt.Json            # Nested structures
})

# Insert structured data
json_table.insert([
    {
        'metadata': {
            'source': 'api',
            'version': '1.0',
            'tags': ['test', 'example']
        },
    'config': {
        'mode': 'testing',
        'parameters': {
            'batch_size': 32,
            'learning_rate': 0.001
        }
        },
        'features': {
            'numeric': [1, 2, 3],
            'categorical': {
                'color': 'red',
                'size': 'large'
            }
        }
    }
])

# Import JSON file
pxt.io.import_json('myproject.from_json', 'data.json',
    schema_overrides={
        'metadata': pxt.Json,
        'config': pxt.Json
    }
)

Image Type

# Create table with image columns
image_table = pxt.create_table('myproject.images', {
    'original': pxt.Image,                  # Any valid image
    'thumbnail': pxt.Image[(224, 224)],     # Fixed size constraint
    'rgb_only': pxt.Image['RGB'],           # Mode constraint
    'thumbnail_rgb': pxt.Image[(64, 64), 'RGB']  # Both constraints
})

# Insert local files
image_table.insert([
    {'original': '/path/to/image1.jpg'},
    {'original': '/path/to/image2.png'}
])

# Insert URLs
image_table.insert([
    {'original': 'https://example.com/image1.jpg'},
    {'original': 'https://example.com/image2.png'}
])

# Insert from cloud storage
image_table.insert([
    {'original': 's3://my-bucket/image1.jpg'}
])

Video Type

# Create table with video columns
video_table = pxt.create_table('myproject.videos', {
    'video': pxt.Video,            # Video file reference
})

# Insert local video files
video_table.insert([
    {'video': '/path/to/video1.mp4'},
    {'video': '/path/to/video2.webm'}
])

# Insert video URLs
video_table.insert([
    {'video': 'https://example.com/video1.mp4'},
    {'video': 'https://example.com/video2.webm'}
])

# Insert from cloud storage
video_table.insert([
    {'video': 's3://my-bucket/video1.mp4'}
])

Audio Type

# Create table with audio columns
audio_table = pxt.create_table('myproject.audio', {
    'audio': pxt.Audio,           # Audio file reference
})

# Insert local audio files
audio_table.insert([
    {'audio': '/path/to/audio1.mp3'},
    {'audio': '/path/to/audio2.wav'}
])

# Insert audio URLs
audio_table.insert([
    {'audio': 'https://example.com/audio1.mp3'},
    {'audio': 'https://example.com/audio2.wav'}
])

# Insert from cloud storage
audio_table.insert([
    {'audio': 's3://my-bucket/audio1.mp3'}
])

Document Type

# Create table with document columns
doc_table = pxt.create_table('myproject.documents', {
    'document': pxt.Document,     # Document file reference
})

# Insert local documents
doc_table.insert([
    {'document': '/path/to/doc1.pdf'},
    {'document': '/path/to/doc2.docx'},
    {'document': '/path/to/text1.md'}
])

# Insert document URLs
doc_table.insert([
    {'document': 'https://example.com/doc1.pdf'},
    {'document': 'https://example.com/doc2.docx'}
])

# Insert from cloud storage
doc_table.insert([
    {'document': 's3://my-bucket/doc1.pdf'}
])

Import Functions

CSV Import

# Basic CSV import with schema inference
table1 = pxt.io.import_csv(
    'myproject.data',
    'data.csv'
)

# CSV import with schema overrides
table2 = pxt.io.import_csv(
    'myproject.data_typed',
    'data.csv',
    schema_overrides={
        'id': pxt.Int,
        'name': pxt.String,
        'score': pxt.Float,
        'active': pxt.Bool,
        'created_at': pxt.Timestamp
    }
)

# CSV import with pandas options
table3 = pxt.io.import_csv(
    'myproject.data_options',
    'data.csv',
    sep=';',                # Custom separator
    encoding='utf-8',       # Specify encoding
    na_values=['NA', '-'],  # Custom NA values
    parse_dates=['date']    # Parse date columns
)

Excel Import

# Basic Excel import
table1 = pxt.io.import_excel(
    'myproject.excel_data',
    'data.xlsx'
)

# Excel import with schema overrides
table2 = pxt.io.import_excel(
    'myproject.excel_typed',
    'data.xlsx',
    schema_overrides={
        'id': pxt.Int,
        'amount': pxt.Float,
        'date': pxt.Timestamp
    }
)

# Excel import with options
table3 = pxt.io.import_excel(
    'myproject.excel_options',
    'data.xlsx',
    sheet_name='Sheet2',    # Specific sheet
    header=1,               # Header row
    na_values=['NA', '-'],  # Custom NA values
    parse_dates=['date']    # Parse date columns
)

Parquet Import

# Basic Parquet import
table1 = pxt.io.import_parquet(
    table='myproject.parquet_data',
    parquet_path='data.parquet'
)

# Parquet import with schema overrides
table2 = pxt.io.import_parquet(
    table='myproject.parquet_typed',
    parquet_path='data.parquet',
    schema_overrides={
        'features': pxt.Array[(100,), pxt.Float],
        'labels': pxt.Array[(10,), pxt.Int]
    }
)

# Import from directory of Parquet files
table3 = pxt.io.import_parquet(
    table='myproject.parquet_dir',
    parquet_path='data/*.parquet'  # Glob pattern
)

JSON Import

# Basic JSON import
table1 = pxt.io.import_json(
    'myproject.json_data',
    'data.json'
)

# JSON import with schema overrides
table2 = pxt.io.import_json(
    'myproject.json_typed',
    'data.json',
    schema_overrides={
        'metadata': pxt.Json,
        'features': pxt.Array[(None,), pxt.Float]
    }
)

# Import from URL
table3 = pxt.io.import_json(
    'myproject.json_url',
    'https://api.example.com/data.json'
)

Hugging Face Dataset Import

import datasets

# Load Hugging Face dataset
dataset = load_dataset('mnist', split='train[:1000]')

# Import with default schema inference
table1 = pxt.io.import_huggingface_dataset(
    'myproject.hf_data',
    dataset
)

# Import with schema overrides
table2 = pxt.io.import_huggingface_dataset(
    'myproject.hf_typed',
    dataset,
    schema_overrides={
        'image': pxt.Image,
        'label': pxt.Int
    }
)

# Import with split information
table3 = pxt.io.import_huggingface_dataset(
    'myproject.hf_split',
    dataset,
    column_name_for_split='split_info'
)

Key Points

All media types (Image, Video, Audio, Document) support local files, URLs, and cloud storage paths
Array types require explicit shape and dtype specifications
JSON type can store any valid JSON data structure
Basic types (Int, Float, Bool, String, Timestamp) match their Python equivalents
Import functions support schema overrides to ensure correct type assignment
Use batch inserts for better performance when adding multiple rows
Cloud storage paths (s3://) require appropriate credentials to be configured

Welcome to Pixeltable

Multimodal AI Datastore

Tutorials

Libraries

Bringing Data

Working with Data in Pixeltable

Supported Data Types & Formats

Import Functions

Key Points

Welcome to Pixeltable

Multimodal AI Datastore

Tutorials

Libraries

​Working with Data in Pixeltable

​Supported Data Types & Formats

​Import Functions

​Key Points

Working with Data in Pixeltable

Supported Data Types & Formats

Import Functions

Key Points