Function generate_python_graphql 

pub fn generate_python_graphql(schema: &str, target: &str) -> Result<String>

Generate Python GraphQL code from a schema

Parses the GraphQL schema string and generates complete Python code with type definitions, resolver implementations, and schema configuration based on the target specification. Generated code follows Python 3.10+ conventions using msgspec for type-safe data serialization and Ariadne for GraphQL schema binding.

Generated Code Features

• Type Definitions: Python dataclasses using msgspec.Struct with frozen=True and kw_only=True for immutability and explicitness
• Enums: Python enums inheriting from str for GraphQL enum types
• Input Objects: msgspec Structs for GraphQL input types
• Union Types: Python type aliases (e.g., User | Post | Any)
• Type Hints: Full type annotations using Python 3.10+ syntax (e.g., str | None instead of Optional[str], list[Item] instead of List[Item])
• Resolvers: Async resolver functions with proper type hints and parameter handling
• Schema Definition: Ariadne-compatible schema with embedded SDL and resolver setup
• Docstrings: NumPy-style docstrings extracted from GraphQL descriptions

Arguments

• schema - GraphQL schema as a string (SDL format)
• target - Generation target specifying what to generate:
  • "all" - Complete code: types, resolvers, and schema definition
  • "types" - Type definitions and enums only
  • "resolvers" - Async resolver function stubs with type hints
  • "schema" - Ariadne schema definition with embedded SDL
  • Any other value defaults to “all”

Returns

Generated Python code as a String, or an anyhow::Error if parsing or generation fails (e.g., invalid GraphQL SDL syntax).

Type Mapping

GraphQL types are mapped to Python as follows:

• String → str
• Int → int
• Float → float
• Boolean → bool
• ID → str
• Custom scalars → str (unless defined in schema)
• Nullable types → T | None (e.g., str | None)
• List types → list[T] (e.g., list[str] or list[str | None])
• Union types → Type1 | Type2 | ... | Any

Examples

Generate all Python code for a simple query:

let schema = r#"
type Query {
  hello: String!
  user(id: ID!): User
}

type User {
  id: ID!
  name: String!
  email: String
}
"#;

let code = generate_python_graphql(schema, "all")?;
println!("{}", code);

Generate only type definitions:

let code = generate_python_graphql(schema, "types")?;
// Contains: msgspec Structs, Enums, type unions

Generate resolver function stubs:

let code = generate_python_graphql(schema, "resolvers")?;
// Contains: async def resolve_* functions with type hints