py-graphql-mapper

py-graphql-mapper

A python library to interact with GraphQL APIs with no need of hardcoded strings.

Introduction

This library acts as a mapper between python and GraphQL languages for GraphQL clients, allowing a code-first approach when calling a GraphQL API server. It translates GraphQL entities into python objects and viceversa in order to avoid working with massive "copy&paste"s.

This document contains a quick overview of the functionalities, for more details and options you can read here:

• Code Generation
• Core Mapper
• Use Cases

The package does not use any third-party libraries, it relies only on python 3 (3.10+) standard libraries.

Usage in a nutshell

Installation

Available in PyPI, the following command will install the library:

pip install py-graphql-mapper

Generate python code from schema

To generate the code execute the following command:

pgmcodegen generate ./pathToOutputFolder -apiArgs ./<pathToArgsFile>/generatorArgs.json

This command requires a json file containing the parameters needed to get the GraphQL schema

A sample is available in the main folder 'cli_args.json'.

The following python files will be generated:

• enums.py
• scalars.py
• gql_simple_types.py
• gql_types.py
• type_refs.py
• queries.py
• mutations.py

These links show code generated using the library Github GraphQL API, Rapid GraphQL API and GeoDBCities API

More command options are available here

Execution of a query

Choose the query class you want to use from the generated file queries.py (or a mutation from mutations.py):

Instantiate it adding GraphQL arguments if needed:

from .output.gdbc.queries import currencies

my_currencies = currencies(last=7, before='MTE=')

or add them using the field args

my_currencies._args.last = 7
my_currencies._args.before = 'MTE='

Then call export_gql_source property to pass the payload to the HTTP request:

(example using requests library)

import requests

response = requests.request('POST', url='https://geodb-cities-graphql.p.rapidapi.com/',
                            json= { "query": my_currencies.export_gql_source },
                            headers={
                                    "content-type": "application/json",
                                        "X-RapidAPI-Key": '123402mmri02fni230iif32jr420',
                                        "X-RapidAPI-Host": "geodb-cities-graphql.p.rapidapi.com"
                                    }
                            )

More details on how to set a query here

Retrieval of a response

Obtained the response from the GraphQL API the following code will map the received json payload into the python object

from pygqlmap.network import GQLResponse

gqlResponse = GQLResponse(response)

gqlResponse.map_gqldata_to_obj(myCurrenciesQuery.type)

print('Result object: ' + str(gqlResponse.result_obj))

The mapped response from the GraphQL server will be available within gqlResponse object: _gqlResponse.result_obj_

More details here

A suite of use cases here