pytq 0.0.4

A Task Queue Scheduler Framework.

Welcome to pytq Documentation

pytq (Python Task Queue) is a task scheduler library.

Problem we solve:

1. You have N task to do.

2. each task has input_data, and after been processed, we got output_data.

pytq provide these feature out-of-the-box (And it’s all customizable).

1. Save output_data to data-persistence system.

2. Filter out duplicate input data.

3. Built-in Multi thread processor boost the speed.

4. Nice built-in log system.

5. And its easy to define how you gonna:

   • process your input_data

   • integrate with your data persistence system

   • filter duplicates input_data

   • retrive output_data

Example

Suppose you have some url to crawl, and you don’t want to crawl those url you successfully crawled, and also you want to save your crawled data in database.

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
This script implement multi-thread safe, a sqlite backed task queue scheduler.
"""

from pytq import SqliteDictScheduler


# Define your input_data model
class UrlRequest(object):
    def __init__(self, url, context_data=None):
        self.url = url # your have url to crawl
        self.context_data = context_data # and maybe some context data to use


class Scheduler(SqliteDictScheduler):
    # (Required) define how you gonna process your data
    def user_process(self, input_data):
        # you need to implement get_html_from_url yourself
        html = get_html_from_url(input_data.url)

        # you need to implement parse_html yourself
        output_data = parse_html(html)
        return output_data

s = Scheduler(user_db_path="example.sqlite")

# let's have some urls
input_data_queue = [
    UrlRequest(url="https://pypi.python.org/pypi/pytq"),
    UrlRequest(url="https://pypi.python.org/pypi/crawlib"),
    UrlRequest(url="https://pypi.python.org/pypi/loggerFactory"),
]

# execute multi thread process
s.do(input_data_queue, multiprocess=True)

# print output
for id, outpupt_data in s.items():
    ...

Customize:

class Scheduler(SqliteDictScheduler):
    # (Optional) define the identifier of input_data (for duplicate)
    def user_hash_input(self, input_data):
        return input_data.url

    # (Optional) define how do you save output_data to database
    # Here we just use the default one
    def user_post_process(self, task):
        self._default_post_process(task)

    # (Optional) define how do you skip crawled url
    # Here we just use the default one
    def user_is_duplicate(self, task):
        return self._default_is_duplicate(task)

TODO: more example is coming.

Quick Links

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Install

pytq is released on PyPI, so all you need is:

$ pip install pytq

To upgrade to latest version:

$ pip install --upgrade pytq