How to use GraphQL with Python in easy steps 2023

GraphQL is a powerful query language for your API, It offers a more effective and adaptable substitute for the conventional REST architecture. In this article, we’ll look at GraphQL’s definition and practical Python applications. We will explained the information you need, whether you’re a developer trying to improve your API design or just interested in this technology. Let’s see, How to use GraphQL with Python.

What is GraphQL?

A query language for APIs, GraphQL was created by Facebook in 2012 and then made available to the public in 2015. Client requests can be limited to the information they actually require, reducing data over- or under-fetching. GraphQL gives clients the ability to dynamically shape their responses, in contrast to REST, where each endpoint typically corresponds to a fixed set of data.

Key GraphQL Features

  • All queries and changes in GraphQL APIs have a single endpoint, which makes management simpler.
  • Precise Data Retrieval: Customers can choose exactly what data they need, which lowers data transfer costs.
  • Strongly Typed: By defining the data’s structure, GraphQL schemas make type checking and auto-documentation possible.
  • Real-time updates: For dynamic applications, GraphQL subscriptions offer real-time data streaming.

How to use GraphQL with Python

You can use a variety of tools and frameworks to use GraphQL in Python, with Graphene and Ariadne being two well-known choices. Let’s look at how to begin with both:

Using Graphene

Graphene is a popular Python library for building GraphQL APIs. Here’s a basic example of setting up a GraphQL server using Graphene:

#Install Graphene using pip

pip install graphene

# Example code

import graphene
class Query(graphene.ObjectType):
hello = graphene.String()

def resolve_hello(self, info):
    return "Hello, GraphQL in Python!"

schema = graphene.Schema(query=Query)

#Execute a query

result = schema.execute('{ hello }')
print(result.data['hello'])

Using Ariadne

Ariadne is another Python library that simplifies building GraphQL servers. Here’s a quick example:

#Install Ariadne using pip

pip install ariadne

#Example code

from ariadne import gql, make_executable_schema, graphql

type_defs = gql("""
type Query {
hello: String!
}
""")

def resolve_hello(_, info):
return "Hello, GraphQL in Python!"

schema = make_executable_schema(type_defs, {"Query": {"hello": resolve_hello}})

#Execute a query

query = '{ hello }'
result = graphql(schema, query)
print(result['data']['hello'])

How do you pass variables in GraphQL query with Python?

  1. Construct Query String: Begin by creating your GraphQL query as a string. Instead of hardcoding the values you want to pass, use placeholders for the variables. For example:
query_string = '''
query GetPerson($id: Int!) {
person(id: $id) {
name
age
}
}
'''

In this example, $id is a variable we want to pass to the person query.

2. Define Variables Dictionary: Create a dictionary that holds the values for your variables. Make sure the dictionary keys match the variable names used in your query. For our example:

variables = {
'id': 123
}

Here, we’re providing a value of ‘123’ for the ‘$id’ variable.

3. Execute the Query: Use your GraphQL client library (e.g., Graphene or Ariadne) to execute the query and pass the variables. In most libraries, you can do this as follows:

result = execute(query_string, variables=variables)

The library will replace the placeholders in your query with the values from the variables dictionary when making the request to the GraphQL server. By following these steps, you can pass variables in a GraphQL query using Python, allowing you to make dynamic and parameterized queries to your GraphQL API.

FAQs about GraphQL

Is GraphQL only for JavaScript-based projects?

No, GraphQL can be used with various programming languages, including Python, Java, Ruby, and more. It’s not limited to JavaScript.

How does GraphQL compare to REST?

Unlike REST, which has fixed endpoints, GraphQL allows clients to request specific data, reducing over-fetching or under-fetching. It’s more flexible and efficient.

Are there any security concerns with GraphQL?

Security is a crucial aspect of any API. With proper authorization and validation, you can secure GraphQL endpoints effectively.

Can I use GraphQL with a relational database?

Yes, GraphQL can be used with relational databases like PostgreSQL or MySQL. You can define resolvers to fetch and update data from these databases.

Is GraphQL suitable for real-time applications?

Yes, GraphQL subscriptions enable real-time updates, making it an excellent choice for applications that require live data.

What is the best language to build a GraphQL API?

Some popular choices include JavaScript with libraries like Node.js for its extensive GraphQL support, Python with Graphene or Ariadne for simplicity and readability, and Ruby with libraries like GraphQL-Ruby for its developer-friendly ecosystem. Additionally, languages like Java, Go, and .NET Core offer robust GraphQL implementations for enterprise-level applications.

What is Codegen in GraphQL?

The GraphQL ecosystem’s Codegen, often known as code generation, is a potent tool that automates the process of creating code from your GraphQL schema. By automatically producing client- and server-side code, it streamlines the creation of GraphQL-based applications and saves human coding time. Codegen creates strongly-typed query and modification operations on the client side using languages like TypeScript or Swift. This guarantees type-safe and effective interactions between your frontend code and the GraphQL API, avoiding runtime errors and enhancing developer productivity. Codegen may generate resolvers and data models on the server side based on your GraphQL schema, hastening the execution of the server logic.



Leave a Comment