Python fastavro example. Python code for working with Avro files.

Python fastavro example. 6. Oct 13, 2020 · I am having trouble decoding an Avro message in Python (3. In one test case, it takes about 14 seconds to iterate through a file of 10,000 records. 4. Taking the following example, using the fastavro package, first write out some initial records, with corresponding schema: from Nov 19, 2015 · 1 So following the answer here: Encode an object with Avro to a byte array in Python I am able to send messages through ZeroMQ - but the performance is brutally slow. Jul 31, 2025 · The fastavro library was written to offer performance comparable to the Java library. If you’d like to try the example code, you’ll find it here. BytesIO' obje Hi, Has anyone done Avro serialization and deserialization of Kafka messages in a AWS Lambda function? So your Lambda function gets the Event (JSON), you grab the base64 kafka message from the "value" field and you decode it into bytes. Tip no 1: Use the correct package Instead of using the official p Dec 19, 2022 · Here are some quick helpful tips for using Avro file format correctly in python. On a test case of about 10K records, it takes about 14sec to iterate over all of them. So you just need to change the last line to fastavro. 7, using Avro, I'd like to encode an object to a byte array. Mar 10, 2022 · scottbelden commented on Mar 10, 2022 I think this is just the difference in how Python represents null in memory. Classes are written one per file, using the namespace to create a directory structure. Upon further inspection even the example code in the documentation throws the same error. Oct 30, 2023 · fastavro. Oct 11, 2024 · The FastAvro library has a function for storing serialized data without a schema, which significantly reduces the amount of stored data https://fastavro. $ pip install pandavro Description It prepares like pandas APIs: read_avro Read the records from Avro file and fit them into pandas DataFrame using fastavro. The Mar 29, 2017 · so the problem isn't fastavro/avro unable to handle bytes type in avro files, the avro-record-to-python-dict decoding has no problem; but it's because Python's json. html As an example: Mar 25, 2023 · The goal of this article is to learn how to use Spark Streaming to process real-time AVRO data that we will consume from Confluent Kafka with Python. 9sec, and if you use it with PyPy it'll Apr 28, 2023 · With several Data Serialisation options available in Python , let us create simple python classes to serialise data in pandas data frame… import pandas import fastavro def avro_df (filepath, encoding): # Open file stream with open (filepath, encoding) as fp: # Configure Avro reader reader = fastavro. validation. readthedocs. The code below is taken from the fastavro page; I have altered the time field in the schema definition by annotating it with the logical type time-millis, in accordance with the current Fast Avro for Python. Dec 19, 2022 · Here are some quick helpful tips for using Avro file format correctly in python. 5sec (to be fair, the JAVA benchmark is fastavro is an alternative implementation that is much faster. The following code uses Avro schema encoder in order to encode a message, which succeeds only if we We would like to show you a description here but the site won’t allow us. All examples I've found write to a file. 9 with Confluent Kafka 1. Reading AVRO files in Python can be efficiently done using the `fastavro` or `avro-python3` libraries. I am trying to do a simple conversion to avro using the fastavro library, as the speed of the native apache avro library is just a bit too slow. getvalue - 2 examples found. pip3 install fastavro The first thing you will also have to do when starting to create a Avro dataset is going to be reading in or creating the Schema. py May 14, 2024 · This example demonstrates a simple way to generate Avro data using Python and utilizing Python libraries like fastavro and psycopg2 to import the data into the PostgreSQL database. 7/gettingstartedpython. timestamp (datetime. For a demonstration purpose, I use a simple avro schema with 2 columns col1 & col2. org/docs/1. Jan 10, 2018 · Another benefit of using fastavro is that you can install it the same way in both Python 2 and Python 3. In comparison the JAVA avro SDK does it in about 1. I've tried using io. schema. ---This video is based on the question htt Jun 22, 2021 · My code in as provided in question. Jan 25, 2023 · This post looks at three ways to write Avro files: the Apache Java library, the Apache Python library, and the fastavro library for Python. In their example they show how you can write a record at a time into a binary avro file. ItemId" not a valid Avro schema: Could not make an Avro Schema object from com. 5 Jul 17, 2023 · Can you please provide a minimal reproducible example? Also, please pretty-print the JSON in your question. Nov 10, 2021 · By default, fastavro will decode a timestamp-millis into a datetime object. Validate the avro file by reading it back into pandas dataframe. Aug 28, 2025 · This is a short guide for getting started with Apache Avro™ using Python. Using Nov 5, 2020 · you can try with fastavro and rec_avro module, here's some example from fastavro import writer, reader, schema from rec_avro import to_rec_avro_destructive, from_rec_avro_destructive, rec_avro_schema def json_objects(): return [{'a': 'a'}, {'b':'b'}] # For efficiency, to_rec_avro_destructive() destroys rec, and reuses it's # data structures to construct avro_objects avroObjects = (to_rec_avro fastavro The current Python avro package is dog slow. Aug 26, 2025 · pandavro The interface between Apache Avro and pandas DataFrame. 5 seconds (to be fair, the JAVA benchmark is doing some extra JSON encoding/decoding). 9 seconds. 11 Python 3. 9sec, and if you use it with PyPy it’ll do it in 1. validate(records[0], parsed_schema). Jan 15, 2025 · We can use popular tools such as Apache Avro’s avro-tools or libraries like Python’s fastavro or avro-python3. If I use datetime. The schema for this custom logical type will use the type string and can use whatever name you would like as the logicalType. Aug 27, 2024 · Depending on your needs, the serialization format could vary. To accommodate this, we can use the named_schemas argument to pass a shared dictionary when fastavro is an alternative implementation that is much faster. The article describes the use of the AVRO serialization format in python, provides a brief description of the AVRO-scheme with explanations of the most unobvious moments, provides specific examples of python code. BytesIO object like so: Sometimes you might have two schemas where one schema references another. Then write the data into avro file format. The fastavro API is also the same for both Python 2 and 3. 12 Python 3. These are the top rated real world Python examples of fastavro. 5sec (to be fair, the JAVA benchmark is doing some extra JSON encoding/decoding). Note: I am asumming you familair with Apache Avro file format, its advantages, its shortcomings, etc. I seem to overwrite in each run. I would like to convert the below JSON data to avro format, I used the below code snippet to write the JSON data in avro format but received an error. 5sec (to be fair, the JAVA benchmark We would like to show you a description here but the site won’t allow us. 6 Python 2. utils ¶ generate_one (schema: Union [str, List [T], Dict [KT, VT]]) → Any ¶ Returns a single instance of arbitrary data that conforms to the schema. The return of deserialize_avro UDF function is a tuple respective to number of Aug 24, 2021 · I am new in avro and I have a avro file to deserialize. How can I do this with Python 3? I have solved each problem separately but not in conjunction, I have only seen a solution to this but using Java and I cannot transpose it to Python. With regular CPython, fastavro uses C extensions which allow it . apache. At this point, is it better to use the fastavro library to deserialize the message bytes or use the confluent_kafka library? Has anyone tried both? Thank you Aug 23, 2021 · But it raises: avro. See ``avro_consumer. 9 Python 3. Serialization process in Apache Avro: Apache Avro offers two types of serialization formats: Binary format - For production use JSON format - For debugging purposes and this article will focus on the binary format. This is the closest solution that I have found in Spark's example folder. Jan 15, 2022 · Improve this answer answered Jan 16, 2022 at 21:08 2,084 12 11 python namespaces schema avro fastavro fastavro. Sep 12, 2018 · I am trying to use fixed datatype when generating an Avro schema, but when I try to use it, I get an error. Is the manual specifying schema file in python arvo package by design? May 17, 2020 · The Apache Avro Python is written in pure Python while fastavro is written in CPython. It iterates over the same 10K records in 2. 10 Python 3. If you were to try to parse the parent schema on its own, you would get an exception because the child schema isn’t defined. So I think that the problem may be that I'm providing the bytes incorrectly. py`` in the examples directory in the examples directory for example usage. fastavro - Man Page Name fastavro — fastavro Documentation The current Python avro package is dog slow. io/en/latest/utils. However, you need to submi Jan 14, 2021 · However using the private API function fastavro. The Python example in this article defines a complex type Conference and serializes data using Apache Avro. example. DataFrame. I have tried both the avro and fastavro packages. Below schema is one of those schemas and used in different schemas as a type. g. avro. 1. Contribute to confluentinc/confluent-kafka-python development by creating an account on GitHub. schema_str (str, Schema, optional): Avro reader schema declaration Accepts either a string or a :py:class:`Schema` instance. In this pose, we describe common issues/solutions Jul 29, 2014 · Found another package called fastavro (https://pypi. You can conveniently do that from Python or e. 0, avro-python3 1. SchemaParseException: Could not make an Avro Schema object from com. With PyPy, this drops to 1. If you are comfortable with Python the fastavro library has utilities to generate data from the schema: https://fastavro. Feb 5, 2023 · With mall datasets from Kaggle, will read the data into pandas dataframe then create the AVRO schema and convert the pandas dataframe into records. By comparison, the JAVA avro SDK reads the same file in 1. 0 installed via pip I have tried running the following script: Oct 6, 2022 · Note: Technically you should only have to write "aliases": ["generated"] but it looks like there is a bug in fastavro where it is not handling that case correctly, but putting the fully namespaced name will work. Setup: Clone Big Data Cluster repo. fastavro is an alternative implementation that is much faster. Feb 22, 2022 · I'm exploring the avro file format and am currently struggling to append data. 13 PyPy3 Supported Features File Writer File Reader (iterating via records or blocks) Schemaless Writer Schemaless Reader JSON Writer JSON Reader Codecs (Snappy, Deflate, Zstandard, Bzip2, LZ4, XZ) Schema resolution Aliases Logical Types Fast Avro for Python. It prepares like pandas APIs: read_avro Read the records from Avro file and fit them into pandas DataFrame using fastavro. html. avsc files and from the schema object generated, creates classes. readthedocs Hi, I tried to append to an existing avro file using fastavro and got the error. using jq on the commandline. As denoted in below code snippet, main Kafka message is carried in values column of kafka_df. What can and can't pandavro May 5, 2011 · The avro Python package available on PyPI is pure Python, so I'm not surprised if it is slower than Java by an order of magniture or more. Installation pandavro is available to install from PyPI. now () instead of int (datetime. There is an Avro C implementation, but to my knowledge nobody has yet created a Python extension based on it. Mar 27, 2020 · A bit new to avro &amp; python. BytesIO () but this gives: AttributeError: '_io. Apr 22, 2015 · In python 2. The fastavro library was written to offer performance comparable to the Java library. 5 and avro 1. Tip no 1: Use the correct package Instead of using the official p Jul 15, 2024 · First, you must define what you mean by "Correct" scheme. org/pypi/fastavro) can extract avro schema. 7 seconds. In this article, we will discuss below four types: Pickle — the Python native format JSON Avro Parquet Python Serialization with Apr 23, 2020 · There is nothing in the official avro spec to suggest that defaulting values should be any different between union fields including null and those not. SchemaParseException: Type property "com. Using Avro from Python tends to be unnecessarily error-prone, especially for a beginners. For example, if I have a field that has a type s I am running Python 3. This is to be expected since the Avro Python implementation is pure Python and we see similar performance comments from the author (s) of FastAvro. However, I need to read in a whole bunch of avro files. 8. Jan 12, 2022 · My Follow-up question of this -> [Avro deserialization from Kafka using fastavro] Is there any way to read all records from avro file (Without Header) using fastavro schemaless_reader () ? Apr 5, 2020 · Do yourself a favor and stick with fastavro. common. fastavro supports the following Python versions: Python 3. If anyone can However, I do not want the schema, as shown below: Another program will read this file with a-priori knowledge of the schema and deserialize each object. Python code for working with Avro files. Versions: Red Hat Enterprise Linux Server release 6. dump unable to serialize a dict where has bytes string nested. The Schema The fo argument is a file-like object so another common example usage would use an io. This will set up an environment for producing Because the Apache Python avro package is written in pure Python, it is relatively slow. Based on the Avro documentation for enumerated types, the schema seems correct, but fastavro fails to recognize the enum type. to_avro Write the rows of pandas DataFrame to Avro file with the original schema infer. fastavro. FastAvro This library implements some fast avro access functions to be used in conjuction with avro_ex or schema_avro libraries. Some schemas use fixed type of data to store MAC addresses. Sep 23, 2020 · Using fastavro as a python library With incredible fast in term of performance, fastavro is chosen as part of deserialized the message. Example using validate Executing the script: Aug 15, 2017 · There are other libraries also, for example, u-msgpack-python, which is implemented in Python and can be vended as a single file. getvalue extracted from open source projects. However, I want to be able to do this programmatically using the Avro python api: https://avro. I found an existing thread here, saying I should not pass in a schema in order to &quot; fastavro is an alternative implementation that is much faster. from_records (records) # Return created DataFrame return df Aug 17, 2020 · Parsing Multiple AVRO (avsc files) which refer each other using python (fastavro) Asked 5 years ago Modified 5 years ago Viewed 3k times Dec 22, 2022 · I have had similar problems on Linux (RHEL 8) using python 3. x avro confluent-schema-registry confluent-kafka-python fastavro asked Oct 24, 2024 at 7:32 merkle 1,835 5 27 47 Learn how to split AVRO schemas into multiple files and reference them using Python's Fastavro library effectively. The issues of schema evolution, RPC, and AVRO-IDL are deliberately excluded from consideration. datetime. AVRO is a popular data serialization format often used in big data applications due to its performance and schema evolution capabilities. 0 and fastavro 1. The sample code is in the following Gist. is there a simple way to generate sample avro files for a given avdl file using Python? Mar 13, 2019 · I'm having some doubts about how fastavro should handle null type. This guide only covers using Avro for data serialization; see Patrick Hunt’s Avro RPC Quick Start for a good introduction to using Avro for RPC. ItemId. validation import validate_many and then your last line would be validate_many(records, parsed_schema). 7. fastavro ¶ The current Python avro package is dog slow. Python: Confluent Kafka + FastAvro (Producer + Consumer) - fastavro. It allows faster access than the pure elixir libraries for use cases like: You need only to read one or a small amount of fields from the avro data but no modify it Jul 21, 2023 · Then, you need to convert Pandas DataFrame into a dict, using fastavro module, you can write the dict to an AVRO file, using this schema. Given a datetime object, you can use the strftime function to convert it to the format you want. python. If you want to validate more than one record, you can do from fastavro. Nov 10, 2022 · I'm looking for a way to modify the schema of an avro file in python. We’ll store the schema of Kafka messages in Avro schema files for FHIR STU3 and example python fastavro usage - Luxas98/fhir-fastavro Feb 6, 2023 · Fastavro-gen uses fastavro to read . How do we read referenced schemas inside a schema? Confluent's Kafka Python Client. It just contains some convenience functions useful when having high amount of avro records to process. Python BytesIO. 11). I don't feel comfortable to simply use the private API, although it works at the moment. In most cases it will be easy to just write a Python dictionary and keep it in memory or a JSON file. I currently use the avro python lib, and null fields are interpreted as optional. 9sec. DataFrame with records df = pandas. However fastavro (v0. With regular CPython, fastavro uses C extensions which allow it to iterate the same 10,000 record file in 1. With each, I show how to write a sample file, and call out any of the quirks that might trip you up. reader (fp) # Load records in memory records = [r for r in reader] # Populate pandas. If it's able to deserialize the message, then it's a functional schema. BytesIO. BytesIO object like so: The fo argument is a file-like object so another common example usage would use an io. For example, running this script: Jan 17, 2020 · I am receiving from a remote server Kafka Avro messages in Python (using the consumer of Confluent Kafka Python library), that represent clickstream data with json dictionaries with fields like user Oct 24, 2024 · python-3. Apr 29, 2020 · I assume you're on Python 3? How does your schema look like? Can the fastavro command line utility read it? Dive into secure and efficient coding practices with our curated list of the top 10 examples showcasing ' fastavro ' in functional components in Python. fastavro is an alternative implementation that is much faster. Feb 21, 2023 · Overview: This article will teach you how to create an Avro producer using the Confluent kafka library in python. validate expects just a single record to validate. compat. 23. Sep 28, 2020 · I have downloaded an AVRO file (with JSON payload) from Microsoft Azure to my Windows 10 computer: Then with python 3. 2) gives nullable unions a default value of null/None automatically. 12 fastavro==0. 21. Aug 8, 2021 · Fast read/write of AVRO files0 Fast read/write of AVRO files Python Packages 08-08-2021 138 words One minute 0 views Contents How to Install fastavro Package Details Classifiers Related Packages Errors Code Examples GitHub Issues I am trying to use a logical type in Avro, with the Python fastavro library to read and write, but the logicalType annotation seems to have no effect at all. now ())) I get "the datum is not an example of the schema" Is it any way to tell python that timezone is UTC (actually it is not UTC) to avoid conversion? Fast Avro for Python. For this example, we’re going to use fastavro (which has a dependency on cramjam). _validate passing in the datum, schema and my named schemas works. Your overall code would look like this. Tak Fast Avro for Python. Finally, we need to tell fastavro to use these functions. json_write json_writer (fo: IO, schema: Union [str, List [T], Dict [KT, VT]], records: Iterable [Any], *, write_union_type: bool = True, validator: bool We would like to show you a description here but the site won’t allow us. Performance of both libraries is compared in this section. Notice for Python 3 users A package called “avro-python3” had been provided to support Python 3 previously, but the codebase was consolidated into the “avro” package Feb 28, 2024 · I would like to generate synthetic data to test my pipelines. Contribute to fastavro/fastavro development by creating an account on GitHub. For the sake of example, let’s assume you have a Parent schema that references a Child schema`. Nov 29, 2019 · When trying to use the official Avro package for python, the package name and API differences between Python 2 and Python 3 create unnecessary confusion. To have the library actually use the custom logical type, we use the name of <avro_type>-<logical_type>, so in this example that name would be We would like to show you a description here but the site won’t allow us. I want to: 1. In this example, let’s suppose we call the logicalType datetime2. Fast Avro for Python. Can you provide example schemas and inputs? I am writing a spark job using python. This makes it difficult to port code over from Python 2. 10. You can rate examples to help us improve the quality of examples. Args: schema_registry_client (SchemaRegistryClient): Confluent Schema Registry client instance. yvl49 90vql guwfhi s4t1m fj yyuvt 28sor o24p 8ff3vys kgsm