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Showing posts from 2016

Bug in (datetime|time).strptime - AttributeError: _strptime

 Issue 7980 This bug occurs only when you use threads and only once. Of course, this method is thread safe, but there is a severe warning. The first use of strptime is not thread secure (underneath _strptime is imported, and the import may throw AttributeError ). If you want to avoid this problem, either you have to call strptime or import _strptime before starting a thread. How to fix it? Just import _strptime or call strptime before starting a thread. It seems that it happens since 2010.

Py.test - Splitting conftest file

If you have to maintain a massive project, you probably have many fixtures in conftest file. And there is a problem; this file grows and grows. So, at some point, you decide to split this huge file into smaller files. But, py.test has to know the fixtures are keeping in these files. So, what you can do? I see three patterns here for this: import these guys inside conftest.py file create more conftest.py files use pytest_plugins Import fixtures inside conftest file You can for example do this: 1 2 3 4 5 6 7 8 9 from tests.my_fixtures.fixs1 import ( fix11, fix12, fix13, fix14, fix15, ... ) from tests.my_fixtures.fixs2 import ( fix21, fix22, fix23, ) from tests.my_fixtures.fixs3 import ( fix31, fix32, fix33 ) But, there are some problems with this approach. You import them in an explicit way, so if you create a new fixture, you have to remember to add this guy in the import clause. So, this strategy is not the best solution. If you have many fi...

DynamoDB in pytest-dbfixtures

pytest-dbfixtures If you use pytest maybe you have heard about pytest-dbfixtures : Pytest dbfixtures is a pytest plugin that makes it a lot easier to set up proper database or storage engine for testing. Simply use one of provided fixtures that start predefined clean database server for your tests or creates server more tailored for your application by using one of provided factories. This plugin is very useful if you have integration tests in your project, and you want to perform tests on a database for example. You will find information how to use it in the documentation . Currently, the plugin supports: Postgresql MySQL Redis Mongo Elasticsearch RabbitMQ And recently, we have added support for DynamoDB . Here , you will find how to run DynamoDB on your computer. And, here we are. If you want to use it in production, you want to test it locally. dynamodb fixture If you still do not use pytest, go to the pytest page and read how to use it, now. If you want to ...

PyCharm - tips, tricks and plugins

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Introduction I have been using Vim for a long time, but recently I have started using PyCharm too. This tool has many proper features and plugins. I will show you some of them. You will find here many gifs instead of text. In this way, you can easily see how it works, how it looks, etc. Plugins   .ignore This plugin was written by my friend. Here is more info about it. It will generate new ignore files for you. BashSupport Supports syntax highlighting, rename refactoring, documentation lookup, inspections, quickfixes, etc. Dash A smart and simple plugin that provides keyboard shortcut access for Dash . KeyPromoter Shows you how easy you can make the same action using only a keyboard. Lua Support for LUA. Markdown Support for markdown. YAML/Ansible support I don't want to write again "Support for YAML/Ansible". Tips & Tricks You do not know what to do? Do not be scared! Just use TODO. You have access to Termin...

AWS Lambda and Python

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What is the AWS Lambda? AWS Lambda lets you run code without provisioning or managing servers. You pay only for the compute time you consume - there is no charge when your code is not running. So, you can build a scalable application without managing servers. Something like a microservice without servers. Serverless! Hence, your function must be written in a stateless style. If you want to store something somewhere, you can connect to S3, Redshift, DynamoDB, etc. AWS Lambda will start to execute your code within milliseconds. I am not going to write a tutorial step by step. You will find here only a handful necessary information. Limits Let's look at the limits (all limits are default, you can ask guys from AWS to increase them). You have access to an ephemeral disk with limit 512 MB (access to /tmp only). Your function must be finished within 300 seconds (it is a default max value; if you want you can set 10 seconds also); if not AWS Lambda will terminate it. Zip...