Skip to main content

basic streaming text processing

Project description

It’s like sed, but Python!

This project is actively being developed but don’t get too attached to any portions of the API or commandline syntax until v1.0.


See the Cookbook for more examples.

Change newline character in a CSV.

$ more sample-data/csv-with-header.csv \
    | pyin "line.replace('\n', '\r\n')" > output.csv

Extract a BigQuery schema from an existing table and pretty print it:

$ bq show --format=json ${DATASET}.${TABLE} \
    | pyin -m json -m pprint "pprint.pformat(json.loads(line)['schema']['fields'])"
[{u'mode': u'NULLABLE', u'name': u'mmsi', u'type': u'STRING'},
{u'mode': u'NULLABLE', u'name': u'longitude', u'type': u'FLOAT'},
{u'mode': u'NULLABLE', u'name': u'latitude', u'type': u'FLOAT'}

Read the first 100K lines of a CSV and write only the lines where column ‘Msg type’ is equal to 5.

$ pyin -i ${INFILE} -o ${OUTFILE} \
    --true \
    --lines 100000 \
    --reader csv.DictReader \
    --import csv \
    --import newlinejson \
    --writer newlinejson.Writer
    "line['Msg type'] == '5'"


Via pip:

$ pip install git+

From master branch:

$ git clone
$ cd pyin && pip install .


It’s easy to completely modify the line content:

$ pyin -i sample-data/csv-with-header.csv "'operation'"

Forgetting to use -t to only get lines that evaluate as True:

$ pyin -i LICENSE.txt "'are' in line"

$ pyin -i LICENSE.txt "'are' in line" -t
modification, are permitted provided that the following conditions are met:
  derived from this software without specific prior written permission.

The --reader-option key=val values are parsed to their Python type but if the user wants to specify something like which JSON library to use for a newlinejson.Reader() instance then they must do that via the --statement option:

$ pyin -i ${INFILE} -o ${OUTFILE}
    --import newlinejson \
    --import ujson
    --reader newlinejson.Reader \
    --writer newlinejson.Writer \
    --statement "newlinejson.JSON = ujson" \
    "'type' in line and line['type'] is 5"



$ git clone
$ cd pyin
$ virtualenv venv
$ source venv/bin/activate
$ pip install -r requirements-dev.txt
$ pip install -e .
$ nosetests --with-coverage
$ pep8 --max-line-length=120

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
pyin-0.4.5.tar.gz (10.8 kB) Copy SHA256 hash SHA256 Source None Apr 30, 2015

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page