Generate a JSON schema for a file

Use pip to install the genson package.

pip install genson

By default, genson generates the JSON schema as a single string without any line breaks or indented whitespace.

To pretty-print the schema that genson produces, install the jq utility.

1. Run the genson command, specifying the path to the input (source) JSON file, and the path to the output (target) JSON schema file to be generated. Use jq to pretty-print the schema’s content into the file to be generated.

   genson "/path/to/input/file.json" | jq '.' > "/path/to/output/schema.json"
   

2. You can find the generated JSON schema file in the output path that you specified.

In your Python project, install the genson package.

pip install genson

1. Set the following local environment variables:

   • Set LOCAL_FILE_INPUT_PATH to the local path to the input (source) JSON file.
   • Set LOCAL_FILE_OUTPUT_PATH to the local path to the output (target) JSON schema file to be generated.

2. Add the following Python code file to your project:

   import os, json
   from genson import SchemaBuilder
   
   def json_schema_from_file(
       input_file_path: str,
       output_schema_path: str
   ) -> None:
       try:
           with open(input_file_path, "r") as file:
               json_data = json.load(file)
   
           builder = SchemaBuilder()
           builder.add_object(json_data)
   
           schema = builder.to_schema()
   
           try:
               with open(output_schema_path, "w") as schema_file:
                   json.dump(schema, schema_file, indent=2)
           except IOError as e:
               raise IOError(f"Error writing to output file: {e}")
           
           print(f"JSON schema successfully generated and saved to '{output_schema_path}'.")
       except FileNotFoundError:
           print(f"Error: Input file '{input_file_path}' not found.")
       except IOError as e:
           print(f"I/O error occurred: {e}")
       except Exception as e:
           print(f"An unexpected error occurred: {e}")
   
   if __name__ == "__main__":
       json_schema_from_file(
           input_file_path=os.getenv("LOCAL_FILE_INPUT_PATH"),
           output_schema_path=os.getenv("LOCAL_FILE_OUTPUT_PATH")
       )
   

3. Run the Python code file.

4. Check the path specified by LOCAL_FILE_OUTPUT_PATH for the generated JSON schema file.