arrow-udf 0.2.1

A user-defined function framework for Apache Arrow

Arrow UDF Python Server

Installation

pip install arrow-udf

Usage

Define functions in a Python file:

# udf.py
from arrow_udf import udf, udtf, UdfServer
import struct
import socket

# Define a scalar function
@udf(input_types=['INT', 'INT'], result_type='INT')
def gcd(x, y):
    while y != 0:
        (x, y) = (y, x % y)
    return x

# Define a scalar function that returns multiple values (within a struct)
@udf(input_types=['BINARY'], result_type='STRUCT<src_addr: STRING, dst_addr: STRING, src_port: INT16, dst_port: INT16>')
def extract_tcp_info(tcp_packet: bytes):
    src_addr, dst_addr = struct.unpack('!4s4s', tcp_packet[12:20])
    src_port, dst_port = struct.unpack('!HH', tcp_packet[20:24])
    src_addr = socket.inet_ntoa(src_addr)
    dst_addr = socket.inet_ntoa(dst_addr)
    return {
        'src_addr': src_addr,
        'dst_addr': dst_addr,
        'src_port': src_port,
        'dst_port': dst_port,
    }

# Define a table function
@udtf(input_types='INT', result_types='INT')
def series(n):
    for i in range(n):
        yield i

# Start a UDF server
if __name__ == '__main__':
    server = UdfServer(location="0.0.0.0:8815")
    server.add_function(gcd)
    server.add_function(extract_tcp_info)
    server.add_function(series)
    server.serve()

Start the UDF server:

python3 udf.py

Data Types

Arrow Type	Python Type
boolean	bool
int8	int
int16	int
int32	int
int64	int
uint8	int
uint16	int
uint32	int
uint64	int
float32	float
float32	float
date32	datetime.date
time64	datetime.time
timestamp	datetime.datetime
interval	MonthDayNano / (int, int, int) (fields can be obtained by months(), days() and nanoseconds() from MonthDayNano)
string	str
binary	bytes
large_string	str
large_binary	bytes

Extension types:

Data type	Metadata	Python Type
decimal	arrowudf.decimal	decimal.Decimal
json	arrowudf.json	any