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Generating Python type annotations from JSON
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| import typing | |
| def convert(it, context: str): | |
| if isinstance(it, dict): | |
| return typing.TypedDict( | |
| context, | |
| { | |
| k: convert(v, f"{context.capitalize()}{k.capitalize()}") | |
| for (k, v) in it.items() | |
| }, | |
| ) | |
| elif isinstance(it, str): | |
| return str | |
| elif isinstance(it, int): | |
| return int | |
| elif isinstance(it, float): | |
| return float | |
| elif it is None: | |
| return typing.Any | |
| else: | |
| raise NotImplementedError(type(it)) | |
| def nested(typedef): | |
| try: | |
| annotations = typedef.__annotations__ | |
| except AttributeError: | |
| pass | |
| else: | |
| for k, v in annotations.items(): | |
| # noinspection PyUnresolvedReferences,PyProtectedMember | |
| if isinstance(v, typing._TypedDictMeta): | |
| yield from nested(v) | |
| yield v | |
| def codegen_typeddict( | |
| it, | |
| default_name: str, | |
| pycharm: bool, | |
| include_undefined: bool, | |
| ): | |
| s = [] | |
| if pycharm: | |
| s.append("# noinspection DuplicatedCode") | |
| classname = it.__name__ or default_name | |
| s.append(f"class {classname}(TypedDict):") | |
| fields = [] | |
| for k, v in it.__annotations__.items(): | |
| try: | |
| v = v.__name__ | |
| except AttributeError: | |
| v = str(v) | |
| if v == "typing.Any" and not include_undefined: | |
| continue | |
| v = v.replace("typing.", "") | |
| fields.append(f" {k}: {v}") | |
| if not fields: | |
| fields = [" pass"] | |
| s.extend(fields) | |
| return "\n".join(s) | |
| def codegen(it, name, pycharm, include_undefined): | |
| typedef = convert(it, context="") | |
| s = [] | |
| imports = ["TypedDict"] | |
| if include_undefined: | |
| imports.append("Any") | |
| s.append(f"from typing import {', '.join(sorted(imports))}") | |
| s.append("") | |
| s.append("") | |
| for d in nested(typedef): | |
| s.append(codegen_typeddict(d, name, pycharm, include_undefined)) | |
| s.append("") | |
| s.append("") | |
| s.append(codegen_typeddict(typedef, name, pycharm, include_undefined)) | |
| return "\n".join(s) | |
| def cli(): | |
| import argparse | |
| import json | |
| import sys | |
| parser = argparse.ArgumentParser() | |
| parser.add_argument( | |
| "input", | |
| type=argparse.FileType("r", encoding="utf-8"), | |
| ) | |
| parser.add_argument( | |
| "-o", | |
| "--output", | |
| type=argparse.FileType("w", encoding="utf-8"), | |
| default=sys.stdout, | |
| ) | |
| parser.add_argument( | |
| "-n", | |
| "--name", | |
| default="Root", | |
| help="Name for the top-level type", | |
| ) | |
| parser.add_argument( | |
| "-p", | |
| "--pycharm", | |
| action="store_true", | |
| help="Include PyCharm metadata", | |
| ) | |
| parser.add_argument( | |
| "-u", | |
| "--undefined", | |
| action="store_true", | |
| help="Include type annotations for undefined values", | |
| ) | |
| args = parser.parse_args() | |
| args.output.write(f'"""\nThis file was generated using {__file__}\n"""\n\n') | |
| args.output.write( | |
| codegen( | |
| json.load(args.input), | |
| args.name, | |
| args.pycharm, | |
| args.undefined, | |
| ) | |
| ) | |
| args.output.write("\n") | |
| if __name__ == "__main__": | |
| cli() |
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