This article has been given a more permanent home on my blog. Also, since it was first written, the development of the Promises/A+ specification has made the original emphasis on Promises/A seem somewhat outdated.
Promises are a software abstraction that makes working with asynchronous operations much more pleasant. In the most basic definition, your code will move from continuation-passing style:
getTweetsFor("domenic", function (err, results) {
// the rest of your code goes here.
| import pytest | |
| def pytest_addoption(parser): | |
| parser.addoption("--integration", action="store_true", help="run integration tests") | |
| def pytest_runtest_setup(item): | |
| if 'integration' in item.keywords: | |
| if not item.config.getoption("--integration"): |
| import asyncio | |
| async def bar(i): | |
| print('started', i) | |
| await asyncio.sleep(1) | |
| print('finished', i) | |
| if i == 5: | |
| raise ValueError("Foo") | |
| return i |
| """ | |
| This script was used to create the figures for http://jrsmith3.github.io/sample-logs-the-secret-to-managing-multi-person-projects.html from a PDF file containing some old CMU sample logs. | |
| """ | |
| import PyPDF2 | |
| from wand.image import Image | |
| import io | |
| import os |
| """ | |
| Problem: | |
| How to Convert PDF to Image with Python Script ? | |
| Installation: | |
| I use ubuntu OS 14.04 | |
| We use wrapper for ImageMagick [http://www.imagemagick.org/script/index.php] to Convert The PDF file | |
| in Python do: | |
| $ sudo apt-get install libmagickwand-dev |
| sudo -i | |
| cd | |
| apt-get install build-essential checkinstall && apt-get build-dep imagemagick -y | |
| wget http://www.imagemagick.org/download/ImageMagick-6.8.7-7.tar.gz | |
| tar xzvf ImageMagick-6.8.9-1.tar.gz | |
| cd ImageMagick-6.8.9-1/ | |
| ./configure --prefix=/opt/imagemagick-6.8 && make | |
| checkinstall |
| git ls-tree -rz --name-only HEAD -- | xargs -0 du -kh | sort -sh -k 1,1 |
| import pandas as pd | |
| import pyarrow as pa | |
| import pyarrow.parquet as pq | |
| fields = [ | |
| pa.field('column1', pa.string()), | |
| pa.field('column2', pa.int64()), | |
| pa.field('column3', pa.string()), | |
| ] |
| import os | |
| import pandas as pd | |
| import pyarrow as pa | |
| import pyarrow.parquet as pq | |
| NUM_FIELDS = 600 | |
| NUM_TABLES = 100 | |
| fields = [ |
| """ | |
| Dockerfile | |
| FROM python:3.6 | |
| RUN apt-get install -y ghostscript \ | |
| libmagickwand-dev | |
| RUN pip install wand PyPDF2 |