yaml2schema: A Python repository from benlawraus

YAML to pyDAL or classes

Generates openapi, pydal and class (or pydantic) definitions of database schema from anvil.yaml or openapi.yaml

Why is it here?

pycharm is awesome. pytest is awesome. pyDAL is awesome. anvil.works is awesome. Why can't we use these mountains of awesomeness together? This repo can used with pyDALAnvilWorks to do just that. When you clone your anvil.works app onto your computer, run this program to generate a pyDAL schema file. You know what I mean if you use pyDAL, it starts something like this:

db.define_table(....

describing your database schema.

Once you got that, you can copy and paste the anvil directory from pyDALAnvilWorks into your anvil.works app.

Now you have a sqlite database for your app and you can use pytest from your pycharm IDE.

What is it for?

pydal is a very good database abstraction layer (DAL) for python handling of just about any database including sqlite.

BUT you do not need to use pyDAL, because you can also use it to generate class definitions of your tables (this repo uses datamodel-code-generator to do that) It also converts your anvil.yaml into openapi.yaml if want to use some other yaml converter.

Once the git repo is downloaded, use an openapi.yaml (or an anvil.yaml) file containing the projects database description. This will read the file and generate a python file with the database tables in openapi form, pydal form and pydantic model form.

How to run it?

First thing is to create a python environment. Once the environment is activated, pip install the dependencies that are at the top of main.py. Then copy the anvil.yaml or an openapi.yaml file into the input directory and run main.py with:

python main.py

The output model and definition files are in the output directory.

File Structure

The file structure is as follows:

main.py # the entire software divided into function files
Input:  tests/yaml/in/anvil.yaml  # file from downloaded anvil.works app
        tests/yaml/in/anvil_refined.yaml # OPTIONAL openapi format of fields requiring more information to specify
        OR
        tests/yaml/in/openapi.yaml
Output: tests/yaml/out/anvil_openapi.yaml  # conversion to openapi standard yaml
        tests/yaml/out/db_models.py  # pydantic type models
        tests/yaml/out/pydal_def.py  # database definition for pyDAL

How to use it?

Here is an example run in the terminal (good for python3.7+):

mkdir work
cd work
python3 -m venv ./venv
source venv/bin/activate
pip3 install datamodel-code-generator
pip3 install strictyaml
git clone https://github.com/benlawraus/yaml2schema.git
cd yaml2schema/src/yaml2schema
# change anvil.yaml or openapi.yaml
python3 main.py
# checkout your changes in the files in the out/ directory

You need to supply a yaml file, either anvil.yaml (created with your repo on anvil.yaml) or openapi.yaml which has the components section of the openapi standard.
Sometimes anvil.yaml is too vague for what you need. You can over-write parts of anvil.yaml with a more detailed specification in anvil_refined.yaml. anvil_refined.yaml needs to be written in openapi yaml though. For example

number

is implemented as integer by default, but you can over-ride to float in anvil_refined.yaml

Included in the src/yaml2schema/input directory, there is an example database schema. You can see what is generated in the src/yaml2schema/output directory.

Implemented

INPUT				OUTPUT
ANVIL		OPENAPI		CLASSES	PYDAL	OPENAPI
TYPE	NOTE	TYPE	FORMAT	TYPE	TYPE	TYPE	FORMAT
string		string		str	string	string
string	pydal only	string	text	str	text	string
number		integer		int	integer	integer	int32
number	anvil_reduced.yaml	integer	int32	int	integer	integer	int32
number	anvil_reduced.yaml	integer	int64	int	bigint	integer	int64
number	anvil_reduced.yaml	number	float	float	double	number	float
datetime		string	date-time	datetime	datetime	string	date-time
date		string	date	date	date	string	date
bool		boolean		bool	boolean
link_single		#ref		class	reference	#ref
link_multiple		array	#ref	List[class]	list: reference	array	#ref
simpleObject	anvil_reduced.yaml	array	integer	List[int]	list:integer	array	integer
simpleObject	anvil_reduced.yaml	array	string	List[str]	list:string	array	string
simpleObject		object		Dict[str,Any]	json	object

Examples anvil_refined.yaml

A meetings table has a discussion field that is a large text body and peoples_names that is a list of strings: In anvil_refined.yaml, for sqlite:

components:
  schemas:
    meetings:
      properties:
        peoples_names:
          type: array
          items:
            type: string
        discussion:
          type: string
          format: text