How to install python 3.5 in CentOS 7 from source

At the time of writing, repository of Centos 7 contains python 3 of version 3.4, which is not the newest. And sometimes it's useful to have newer version. For example, I needed python 3.5. And here I will show you how to install it. We will be installing it from source.

1. Update repositories and install couple packages:

sudo yum update
sudo yum install zlib-devel openssl-devel

How to update openssl and/or install openssl 1.1.0 in centos 7 from sources

Updating openssl

After deploying new centos 7 distro, I checked version of openssl and it appeared to be very old (2013!!). To check openssl version, you can use this command:

openssl version
OpenSSL 1.0.1e-fips 11 Feb 2013

or this:

yum info openssl
Name        : openssl
Arch        : x86_64
Epoch       : 1
Version     : 1.0.1e
Release     : 60.el7_3.1

Then if you want to update it, simply run:

sudo yum update openssl

And if you check it again, it will show updated version:

openssl version
OpenSSL 1.0.2k-fips  26 Jan 2017

So this should include all security fixes and you're good to go.

But if you still want to install newer openssl alongside with the current one, below I will show how.

Caching for anonymous (non-authenticated) users in Django

Hi boys and girls,

Recently I was optimizing performance on some of my django sites and needed to cache all views for anonymous users, but still render for authenticated users. Django documentation is silent on this. I've also checked out stackoverflow, but people there recommend using templates, which I don't like. So below I will give you my version of how to solve that.

Django Haystack - how to limit number of search results

Hello friends,

Recently I needed to limit number of search results in haystack and that was a bit of a challenge. So I decided to share it with you here.

I knew how to limit search results using old style views (haystack.views.SearchView):

from haystack.views import SearchView

class MySearchView(SearchView):

    #limit maximum results
    def get_results(self):
        return self.form.search()[:100]

Fabric how to set environment variable to fix encoding

Hi there,

Today I've encountered with one weird problem and decided to share it with you.

Here is what happens. When I ssh to server manually and run python script - everything works fine. But if I try to run the same script using fabric script, which connects to the same server, then it fails. In particular, it was encoding error:

UnicodeEncodeError: 'ascii' codec can't encode character u'\xaa' in position bb: ordinal not in range(128)

How to scrape https website with proxies

Hi all,

My last post about scraping with proxies is quite old and I decided to write a newer version of it. In particular, today I will emphasize how to scrape https website with proxies.

There are also good news about requests library. Requests has not been supporting socks proxies for quite a long time, but in 2016 there was a new release of it. So now requests fully supports both http and socks proxies.

So let's get started. Below I will show you 4 different examples of how to scrape a single https page. First, we will scrape it with requests using socks and http proxies. Second, we will do the same using urllib3 library.

How to build uwsgi from source and run as a service

As you might have already noticed, I always deploy python applications using uwsgi and nginx. But I didn't write yet how to install uwsgi. Probably there is some version in repository, but I don't really care about it. I know it's old and not what I actually need.

I need to build uwsgi with plugin support, which would allow me to work both with python 3 and 2. Then I will create service config file, so that you can use it as service. Sounds good, isn't it? Let's do it then.

1. Download uwsgi and extract it

cd ~
curl -O http://projects.unbit.it/downloads/uwsgi-2.0.12.tar.gz
tar -xvzf uwsgi-2.0.12.tar.gz