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I had a need for sequentially increasing numbers for use in a template loop with multiple INPUT tags, and I whipped up this simple template tag to help with that.

@register.simple_tag(takes_context=True)
def tabindex(context):
	if 'tabindex' not in context: context['tabindex'] = 0
	context['tabindex'] += 1
	return context['tabindex']

As an example, it could be utilized like the following.

<input type="text" name="fullname" tabindex="{% tabindex %}" />

Each time it’s called, it will self increment.

It could be extended to provide an alternate initial value (instead of 0) with an addition of an argument, but I didn’t need that myself.

I have a Django project where I was utilizing bulk_create to load a fairly large dataset, and this was some times resulting in the error MySQL server has gone away. Reading though the documentation on this error, https://dev.mysql.com/doc/refman/8.0/en/gone-away.html I see that one of the possible causes for this is “you send a query to the server that is incorrect or too large” Turns out, I just needed to use the batch_size parameter of bulk_create. The  success of a website depends on web design, this is why is very important to look for the help the experts from Best Website Hosting. 

In my case, a batch of 56,000 records was triggering the error, so for safety, I switched to using bulk_created(..., batch_size=(10**4)).

Are you in need in calculating a checksum for the contents of a directory? This sequence of commands can help.

I have been using pgAdmin 4 as my GUI tool for interacting with my PostgreSQL database servers. I had noticed the “Application” column, and that it was empty for my Django sessions, and wanted to fill that in with useful context..

Are you trying pip install pycrpto or otherwise trying to configure an application and you run into the following errors?

checking whether we are cross compiling… configure: error: in `/tmp/pip-install-2eizv0ma/pycrypto’:

configure: error: cannot run C compiled programs.

You may run into an issue that originates from improved security practices, and your only hint is in the first line of the error: “/tmp/pip-install-2eizv0ma/pycrypto”

Run the following: mount | grep tmp

If you see the option noexce in the mount point for your “/tmp” path, then that’s the issue — no execution of any file residing on that partition is allowed.

In my case, I was trying to install a Python package via pip which required some compilation of C code, so I was able get around the issue by set the TMPDIR environment variable:

TMPDIR=/path/to/alternate/tmp pip install pycrypto

I recently switched a Django project utilizing Haystack from Whoosh as the engine to Xapian. The performance significantly improved, but I was left with some deficiencies in the search results — this turned out to be due to the default settings.

Here are the necessary settings to improve the search result quality:

import xapian

HAYSTACK_XAPIAN_FLAGS = (
    xapian.QueryParser.FLAG_PHRASE |
    xapian.QueryParser.FLAG_BOOLEAN |
    xapian.QueryParser.FLAG_LOVEHATE |
    xapian.QueryParser.FLAG_WILDCARD |
    xapian.QueryParser.FLAG_PURE_NOT |
    xapian.QueryParser.FLAG_PARTIAL
)
HAYSTACK_XAPIAN_STEMMING_STRATEGY = 'STEM_ALL'

HAYSTACK_CONNECTIONS = {
    'default': {
        'ENGINE': 'xapian_backend.XapianEngine',
        'PATH': root.path('data/xapian')(),
        'FLAGS': HAYSTACK_XAPIAN_FLAGS,
    },
}

Before these settings, I was having problem with queries being apparently case sensitive, at least when using AutoQuery, and failing partial searches. These changes improve case insensitivity and stemming, which still having almost 100x better performance than Whoosh.

Hopefully this helps someone out there looking for solutions.

Today, on a production system errors started arising from a Django based application that made use of PostGIS features. All SQL queries that included any geo data were failing. This was on PostgreSQL 9.6 on Centos 7.

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This is an update to Full page screenshots with Python and Selenium updated to work with Python 3, and fix an issue with single pages.

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I was getting PHP `unseralize` errors when working with some WordPress option values.

PHP Notice: unserialize(): Error at offset 4854 of 24578 bytes

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If you ever find yourself using Apache as a frontend server or reverse proxy, as opposed to one Nginx, for example. You may want to be sure to pass the actual host IP and scheme information back to your application so that it may function properly. By default, mod_proxy sets the X-Forwarded-For header. But that header is a list, and is used by other types of proxies. You may want to set the X-Forwarded-Proto and X-Real-IP as well. The following entries into your VirtualHost or similar should do the job:

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