MySQLdb as I understand doesn't support Python 3. I've heard about PyMySQL as a replacement for this module. But how does it work in production environment?
Is there a big difference in speed between these two? I asking because I will be managing a very active webapp that needs to create entries in the database very often.
PyMySQL is a pure-python database connector for MySQL, and can be used as a drop-in replacement using the install_as_MySQLdb() function. As a pure-python implementation, it will have some more overhead than a connector that uses C code, but it is compatible with other versions of Python, such as Jython and PyPy.
At the time of writing, Django recommends to use the mysqlclient package on Python 3. This fork of MySQLdb is partially written in C for performance, and is compatible with Python 3.3+. You can install it using pip install mysqlclient. As a fork, it uses the same module name, so you only have to install it and Django will use it in its MySQL database engine.
Related
Is there a way to install psycopg2 with pypy. I am trying to run Django with pypy and the main problem I am facing is psycopg2 library.
pypy documentation says that I can install psycopg2cffi library instead, but I don't know how to tell Django postgresql backend to use psycopg2cffi instead of psycopg2. Is there any way I can do that? Is there a way to install psycopg2 with pypy. or more broadly, is there any advantage of using pypy than normal Cpython compiler with Django?
I tried running various python programs using both Cpython and pypy and shockingly pypy was much faster. So, I thought using pypy can actually increase the throughput of APIs by reducing the time of each API, but I haven't found any documentation for the same?
Any leads are welcome!! Thanks in advance.
from: https://pypi.org/project/psycopg2cffi/
To use this package with Django or SQLAlchemy invoke a compatibility
hook (for example, from settings.py in case of Django, or from a
psycopg2.py file in site-packages of your virtual env):
from psycopg2cffi import compat
compat.register()
I'm building a python3 app which requires high-speed connections. Being a pure python library, will PyMySQL be significantly slower than the C based MySQLdb in connecting and executive queries?
Is PyMySQL well supported for future versions of python?
If not, can anyone suggest a reliable alternative?
PyMySQL is implemented in pure Python while MySQLdb is C extension. PyMySQL is easy to install (and some times the only way) in some system while MySQLdb sometimes give problems.
But both are just MySQL python connectors.
Why PyMySQL? MySQL is an immensely popular RDBMS, and you usually need
to talk to it when writing a web application in Python. The defacto
standard, MySQLdb, is a C extension module that has a reputation of
being difficult to compile, especially if you're on a Mac (like I am).
Additionally, end-users need to wait for new binaries to be compiled
for each new release of Python, and MySQLdb will never run on Jython,
IronPython, or PyPy (without something like cpyext or IronClad). We
also maintain 100% compatibility between Python 2 and Python 3, so all
advancements made on the 2.x trunk will be immediately available on
Python 3.
We are developing a drop-in replacement for MySQLdb that "just works"
without the hassle of compiling and installing C extensions and
without worrying what platform you're on.
Source https://code.google.com/p/pymysql/wiki/Goals
Many projects use PyMySQL because it supports Python 3 (3.3 and up) as well as Python 2. At the time of writing it has over 650 forks on Github and over 60 contributors. There are regular updates and patches to it every couple of months or so and it's popular in the Python community for it's relatively easy installation and Python 3 support. So all that said, yes, I would say it's well supported.
Now for speed: since it's written pure Python whereas MySQLdb is C, you can expect PyMySQL to be slower. For an in depth analysis I suggest a look at the openstack link at the bottom of this post. Based on their testing, PyMySQL was roughly 10x slower than MySQLdb. However, with DB calls you are mostly IO bound anyways so the advantage of PyMySQL supporting gevent or something similar for asynchronous IO may make up for the speed depending on your application.
Sources:
https://github.com/PyMySQL/PyMySQL
https://wiki.openstack.org/wiki/PyMySQL_evaluation
There are Python libraries that allow to communicate with a database. Of course, to use these libraries there should be an installed and running database server on the computer (python cannot communicate with something that does not exist).
My question is whether the above written is applicable to the sqlite3 library. Can one say that this library does not need any database to be installed (and running) on the computer? Can one say that sqlite3 needs only a file system?
SQLite only needs a filesystem, yes, it is not a standalone server. Instead, SQLite is an embedded database. The whole database driver is contained in a shared library loaded together with the Python executable, as needed.
You do need to have the libsqlite3 shared library installed; Python itself only includes the Python integration for that library.
For Ubuntu, for example, you'd install the libsqlite3-0 package; but since the Python package already depends on this this is not something you need to worry about, usually. Mac OS X already comes with the shared library installed, and on Windows I believe the Python Windows installer bundles the library with it. The ActiveState Python Windows distribution certainly does, for example.
If you want to compile Python from source, you'll have to install (at the very least) the SQLite development headers to enable compilation of the sqlite3 package.
No, sqlite package is part of Python standard library and as soon as you have Python installed, you may use sqlite functionality.
MartijnPieters noted, the actual shared library is not technically part of Python (this was my a bit oversimplified answer) but comes as shared library, which has to be installed too.
Practically speaking, if you manage installing Python, you have the sqlite available for your Python code.
As OP asked for for a need to install sqlite separately, I will not speculate on how to install Python, which is not able to work with it.
I just solved some problems in my Django 1.3 app by using PyMySQL instead of MySQLdb. I followed this tutorial on how to make the switch: http://web-eng-help.blogspot.com/2010/09/install-mysql-5-for-python-26-and.html
Now I want to know what PyMySQL actually is and how it is different from MySQLdb.
I am using it on localhost and will then upload it to some hosting.
Is it fine to use PyMySQL on localhost and on hosting whatever they provide? Since I have changed "MySQLdb" in base.py and introspection.py to "PyMySQL", will I need to upload it to the server after changing these files? Or as it is Django's files, since Django will be uploaded there already, does it not matter much?
PyMySQL and MySQLdb provide the same functionality - they are both database connectors. The difference is in the implementation where MySQLdb is a C extension and PyMySQL is pure Python.
There are a few reasons to try PyMySQL:
it might be easier to get running on some systems
it works with PyPy
it can be "greened" and works with gevent
The proper way to use it with Django is to import it and tell it to impersonate MySQLdb in your top-level file, usually manage.py. Put the following code at the very top of your manage.py (or whatever file you call when starting your server):
try:
import pymysql
pymysql.install_as_MySQLdb()
except ImportError:
pass
PyMySQL and MySQLdb are both database connectors for Python, libraries to enable Python programs to talk to a MySQL server.
You would normally never upload core Django files when deploying an app. If Django is working fine on your deployment server, you definitely don't need to change anything there. The DB driver is a step or two below the ORM even, and certainly none of the code you have written depends on which of these is in use.
Your first point:
According to pymysql wiki page:
MySQLdb, is a C extension module that has a reputation of being
difficult to compile, especially if you're on a Mac. Additionally,
end-users need to wait for new binaries to be compiled for each new
release of Python, and MySQLdb will never run on Jython, IronPython,
or PyPy (without something like cpyext or IronClad). We also maintain
100% compatibility between Python 2 and Python 3, so all advancements
made on the 2.x trunk will be immediately available on Python 3.
Your second point:
If django is working fine on your localhost, then it should be fine on
your development.
As per my experience I had difficulty in installing "MySQL-python" - (MySQLdb).
It made me search for more alternatives so I found pymysql, and it also got installed easily and worked in first go like a charm.
So I would suggest using pymysql only instead of MySQLdb.
I am starting with these topic, I only want to say an observation: PyMSQL has CPYTHON as a requirement(is optionall perhaps for performance https://pypi.org/project/PyMySQL/#requirements) to install, and Cpyhton depend on 'C', I tested Cpython and I had trouble when installed for the version of C too... then both implementation depend on 'C' [if you want performance], is the same thing for me...if the performance is not problem, perhaps PyMySQL is good without Cpython, free of 'C'. Perhaps we can start with PyMySQL alone with Python and switch Python to Cpython to gain in performance that could be a good thing we have all the things running and after that we can try to switch to Cpython,,,
We need to know the funcionality difference. Why in Django PyMySQL run better for you or give to you solutions for some problems, what problems? That is the important thing for change perhaps. MySQLdb perhaps depend directly from 'C' but PyMSQL indirectly thru Cpython(in case of similar performance), I prefer a direct dependence without limitations of jumps...Greetings.
So, looking for a mysql-db-lib that is compatible with py3k/py3.0/py3000, any ideas? Google turned up nothing.
It appears the MySQLdb is pretty much a dead project. However, PyMySQL is a dbapi compliant, pure-python implementation of a mysql client, and it has python 3 support.
EDIT: There's also MySQL Connector/Python. Same idea.
I was looking for it too, but also found nothing, so I ported MySQL-python-1.2.3 to py3k
you can read it here
http://sourceforge.net/p/mysql-python/discussion/70460/thread/61e3a3c9/
There are currently a few options for using Python 3 with mysql:
https://pypi.python.org/pypi/mysql-connector-python
Officially supported by Oracle
Pure python
A little slow
Not compatible with MySQLdb
https://pypi.python.org/pypi/pymysql
Pure python
Faster than mysql-connector
Almost completely compatible with MySQLdb, after calling pymysql.install_as_MySQLdb()
https://pypi.python.org/pypi/cymysql
fork of pymysql with optional C speedups
https://pypi.python.org/pypi/mysqlclient
Django's recommended library.
Friendly fork of the original MySQLdb, hopes to merge back some day
The fastest implementation, as it is C based.
The most compatible with MySQLdb, as it is a fork
Debian and Ubuntu use it to provide both python-mysqldb andpython3-mysqldb packages.
benchmarks here: https://github.com/methane/mysql-driver-benchmarks
As for future plans of MySQLdb, you might want to ask the author (Andy Dustman).
His blog is here: http://mysql-python.blogspot.com/
Here is a working repository for Python 3: https://github.com/davispuh/MySQL-for-Python-3
not sure if you're still looking, but you could try this:
http://sourceforge.net/projects/mypysql/
You can download the mysql-connector-python module compatible with Python3:
http://rpm.pbone.net/index.php3/stat/4/idpl/15667200/dir/rawhide/com/mysql-connector-python3-0.3.2-2.fc16.noarch.rpm.html
Get the "source RPM", unzip it and use it (e.g. put it in your PYTHONPATH, and look at the examples).
You're probably better off using Python 2.x at the moment. It's going to be a while before all Python packages are ported to 3.x, and I expect writing a library or application with 3.x at the moment would be quite frustrating.
There is an official Python 2/3 library, downloadable from MySQL website.
Oracle released version 1.0.7 to public on 29 September 2012.
It's pure Python and works with MySQL 4.1+
See more details here: http://dev.mysql.com/doc/connector-python/en/connector-python.html
I'm currently using it with MySQL 5.5 and Python 3.2 with no problems thus far :)