Python Guide

This manual covers the dsviper Python API — the Python binding of the Viper runtime. You will learn how to use the type and value system, work with databases, and leverage the full power of Viper from Python.

The Metadata Everywhere Principle

Viper carries its type information as runtime metadata, and every subsystem draws on the same source: types, values, functions, serialization, database persistence, and RPC. You describe your data once — either through the static API generated from a DSM model, or directly through the dynamic API — and the runtime handles conversion, validation, and cross-language interoperability for you. This is why Python natives (list, dict, tuple) can be passed directly to typed dsviper functions: the metadata drives the bridge, so there is nothing to register and nothing to glue by hand.

• Installation
  • Prerequisites
  • Installing from PyPI
  • Installing from the DevKit
  • Verifying Installation
  • Understanding dsviper
  • Strong-Typed Layer Over Python
  • Quick Test
  • What’s Next
• Tutorial
  • The User/Login Model
  • Two Approaches
  • What’s Next
• Types and Values
  • The Universal Constructor
  • Choosing the Right Constructor
  • Type Constants
  • Primitive Types
  • Mathematical Types
  • Type Deduction
  • Type Information
  • Type Checking
  • The Seamless Bridge
  • What’s Next
• Collections
  • Vector
  • Set
  • Map
  • Optional
  • Tuple
  • Variant
  • XArray
  • Any
  • Nested Collections
  • What’s Next
• Structures and Enumerations
  • Creating Structures with Definitions
  • Instantiating Structures
  • Field Access
  • Default Values
  • Nested Structures
  • Paths
  • Enumerations
  • Type Information
  • Using Structures with Databases
  • What’s Next
• Error Handling
  • The ViperError Exception
  • Common Error Categories
  • Best Practices
  • Debugging Tips
  • What’s Next
• DSM Processing
  • The DSM Workflow
  • Step 1: Assemble
  • Step 2: Parse
  • Step 3: DSM Introspection
  • Using Runtime Definitions
  • Serialization
  • What’s Next
• Database
  • Creating a Database
  • Remote Access
  • Setting Up Definitions
  • CRUD Operations
  • Transactions
  • Lifecycle
  • Metadata
  • Choosing Between Database and CommitDatabase
  • What’s Next
• Commit System
  • CommitDatabase
  • Opening a CommitDatabase
  • Reading State
  • Mutations
  • Complete Example
  • Path-Based Mutators
  • Commit History
  • Embedded Definitions
  • What’s Next
• The Dual-Layer Contract
  • The Contract
  • Why the Engine’s Output Is Untrusted Data
  • Three Error Families
  • What Commit Provides
  • What Commit Does NOT Provide
  • Implications for dsviper Code
  • Summary
  • See Also
• Binary Data (Blobs)
  • Blob vs BlobId
  • ValueBlob
  • ValueBlobId
  • BlobLayout - Metadata Everywhere
  • BlobView (Read-Only)
  • BlobArray (Read-Write)
  • BlobPack - Structured Binary Data
  • NumPy Integration
  • Blob in Attachments
  • Storing Blobs in Database
  • When to Use Each Type
  • What’s Next
• Serialization
  • JSON Encoding
  • DSM Definitions Serialization
  • Binary Encoding
  • Stream Codec
  • Value Description
  • Binary File Format
  • Common Patterns
  • Summary
  • What’s Next