structlog-round

A simple and light-weight structlog processor to round floats for prettier logging.

Are you using structlog for convenient, structured logging in your Python program? Logging floats easily bloats your logs through many floating point digits? structlog-round rounds your floats for prettier logging but lets you keep full float precision inside your program.

For example:

log.msg("Hello world", a=1/3, b=2/3, ab_list=[1/3, 2/3])

# without structlog-round: prints long and ugly floats
# 2020-07-16 21:48.21 Hello world        a=0.3333333333333333 b=0.6666666666666666 ab_list=[0.3333333333333333, 0.6666666666666666]

# with structlog-round: floats are logged nicely rounded
# 2020-07-16 21:48.21 Hello world        a=0.333 b=0.667 ab_list=[0.333, 0.667]

structlog-round lets you configure how floats are rounded and also supports rounding floats in (nested) lists, dicts, or numpy arrays.

Install

pip install structlog-round

Or for development:

git clone git@github.com:stefanbschneider/structlog-round.git
python setup.py install
# dependencies for testing
pip install -e .[dev]

Usage

import structlog
import structlog_round

structlog.configure(
    processors=[
        # importing and adding FloatRounder to your list of processors is all you have to do
        structlog_round.FloatRounder(digits=3),
        structlog.dev.ConsoleRenderer()
    ]
)
log = structlog.get_logger()

a = 1/3
b = 2/3
log.msg("Hello world", a=a, b=b)
# this log is easily readable with short, rounded floats
# Hello world                    a=0.333 b=0.667
print(a, b)
# the floats are still available in full precision and unrounded
# 0.3333333333333333 0.6666666666666666

FloatRounder has the following configuration options:

• digits: The number of digits to round to
• only_fields: A list of only fields that should be rounded
• not_fields: A list of fields that should not be rounded
• np_array_to_list (bool): Whether to cast numpy arrays to lists and round floats for prettier logging