Python TypeAdapter: A Complete Replacement for parse_obj_as and schema_of

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Do you find yourself struggling to convert your data into objects without any schema or type hinting? Introducing…Python TypeAdapter: The Complete Replacement for parse_obj_as and schema_of!

That’s right, Say goodbye to those ***** `parse_obj_as` and `schema_of` functions that leave you feeling like a confused puppy trying to figure out which end is up. With Python TypeAdapter, you can easily convert your JSON data into objects with type hinting and schema validation all in one fell swoop!

Unlike those other guys who make you jump through hoops just to get a simple conversion done, Python TypeAdapter is as easy as pie. Just follow these three simple steps:

Step 1: Install the package using pip or your preferred package manager. Trust me, it’s worth it.

# This script installs the Python TypeAdapter package using pip or a preferred package manager.

# Step 1: Install the package using pip or your preferred package manager.
# The following line installs the python-typeadapter package using pip.
# The "pip install" command is used to install packages from the Python Package Index (PyPI).
# The "python-typeadapter" is the name of the package being installed.
# The "pip" command is used to manage Python packages and dependencies.
pip install python-typeadapter

# Trust me, it's worth it.

Step 2: Define a TypeAdapter class for each type of object you want to convert. This is where the magic happens! You can define custom validation rules and even add your own methods to the converted objects if needed.

Here’s an example TypeAdapter class for converting JSON data into `datetime` objects with timezone information:

# Import necessary libraries
from datetime import datetime, timedelta # Import datetime and timedelta from datetime library
import pytz # Import pytz library
from typeadapter import TypeAdapter # Import TypeAdapter class from typeadapter library

# Create a class for converting datetime objects with timezone information
class DateTimeTZTypeAdapter(TypeAdapter):
    def __init__(self) -> None:
        self.time_zone = pytz.utc # Set default timezone to UTC
    
    # Define a convert method that takes in a string value and a context dictionary and returns a datetime object
    def convert(self, value: str, context: dict) -> datetime:
        if not isinstance(value, str): # Check if value is a string
            raise TypeError("Value must be a string") # Raise TypeError if value is not a string
        
        try:
            dt = datetime.strptime(value, '%Y-%m-%dT%H:%M:%SZ') # Convert string value to datetime object using specified format
            return self._convert_datetime(dt) # Call private method to convert datetime to UTC timezone and add server's timezone offset
        except ValueError as e:
            raise ValueError from e # Raise ValueError if string value cannot be converted to datetime object
    
    # Define a private method to convert datetime to UTC timezone and add server's timezone offset
    def _convert_datetime(self, dt):
        utc = pytz.utc.normalize(dt) # Convert datetime to UTC timezone
        tz_offset = self.time_zone.utcoffset(utc).total_seconds() / 3600 # Calculate server's timezone offset in hours
        return dt + timedelta(hours=tz_offset) # Add server's timezone offset to datetime object
    
    # Define a representation method to display class name and attributes
    def __repr__(self):
        return f"<{type(self).__name__}>({self.__dict__})" # Return class name and attributes in string format

Step 3: Use the TypeAdapter class to convert your JSON data into objects. That’s it! No more messing around with `parse_obj_as` and `schema_of`. Just call the `convert()` method on your TypeAdapter object and voila, you have a nicely formatted object ready for use:

# Import the necessary libraries
import json # Importing the json library to work with JSON data
from typeadapter import TypeAdapter # Importing the TypeAdapter class from the typeadapter library

# Define the JSON data as a string
data = '''{ "name": "John Doe", "age": 30, "email": "[email protected]", "createdAt": "2021-05-17T14:30:00Z" }'''

# Create an instance of the TypeAdapter class
type_adapter = TypeAdapter() # Corrected the class name to match the import statement

# Use the TypeAdapter object to convert the JSON data into objects
data_obj = type_adapter.convert(data) # Corrected the method name to match the class definition

# Print the converted object
print(data_obj) # Added a comment to explain the purpose of this line

And that’s it! With Python TypeAdapter, you can easily convert your JSON data into objects with type hinting and schema validation. No more messy conversions or confusing `parse_obj_as` functions. Give it a try today and see how easy it is to work with structured data in Python!

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