Python tip[5]

Tip #5

Meet the triumvirate  of python interactive sessions:

help(), dir(), see()

So no doubt you use help, and probably dir, but you are probably wondering about see()... That's because it has to be installed first:

pip install see

What it does: Unless you speak native dunder (double underscore), dir's output can be a little overwhelming. For example, a dir on an int object (everything is an object in python...) gives us:

>>> dir(1)
['__abs__', '__add__', '__and__', '__class__', '__cmp__', '__coerce__', '__delattr__', '__div__', '__divmod__', '__doc__', '__float__', '__floordiv__', '__format__', '__getattribute__', '__getnewargs__', '__hash__', '__hex__', '__index__', '__init__', '__int__', '__invert__', '__long__', '__lshift__', '__mod__', '__mul__', '__neg__', '__new__', '__nonzero__', '__oct__', '__or__', '__pos__', '__pow__', '__radd__', '__rand__', '__rdiv__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rlshift__', '__rmod__', '__rmul__', '__ror__', '__rpow__', '__rrshift__', '__rshift__', '__rsub__', '__rtruediv__', '__rxor__', '__setattr__', '__sizeof__', '__str__', '__sub__', '__subclasshook__', '__truediv__', '__trunc__', '__xor__', 'conjugate', 'denominator', 'imag', 'numerator', 'real']

>>> from see import see
>>> see(1)
    +           -           *           /           //          %           **
    <<          >>          &           ^           |           +obj
    -obj        ~           <           <=          ==          !=          >
    >=          abs()       bool()      divmod()    float()     hash()
    help()      hex()       int()       long()      oct()       repr()
    str()       .conjugate()            .denominator            .imag
    .numerator  .real

A little more human readable, no? Oh, I'm about to hear the complaint about typing from see import see everytime you start up python. Time to go and check tip #2...


François
@f_dion

Python tip[4]

Tip #4

I was mentioning cppcheck on twitter, for those of us who also code in C/C++. I must admit I didn't start using it until I saw Alan (Coopersmith) using it on Xorg about a year ago. So, what do we have for python? Today I'll make a quick mention of Pylint. Install is simple, along the line of (adjust to your package manager):

sudo apt-get install pylint

Then you can go into a python project and do:

pylint your_filename.py

What it does: "Pylint is a tool that checks for errors in Python code, tries to enforce a coding standard and looks for bad code smells", according to pylint.org. It also gives your code an overall mark. It's a good idea to at least run it and look at the suggestions it offers.

Bonus: pylint includes pyreverse which allows one to generate a package and class diagram (UML) from source code. This works ok as long as the code is straight forward.


François
@f_dion

Python tip[3]

Tip #3

As you install new modules (say, with pip install) to support your Python application, add them to a requirements.txt file and do the same for your tests, as test_requirements.txt. Installation is then a simple:

pip install -r requirements.txt

What it does: It allows you to keep track of what packages are needed if you share your code, deploy it to other machines, or if you somehow have to rebuild your computer. You can also quickly test that the list is up to date by creating a virtualenv --no-site-packages, and then using a pip for that virtual environment to do the install.


François
@f_dion

Python tip[2]

Tip #2

In your home directory, in a file named .env.py put the imports you want to always have preloaded in python interactive mode:

from some_module import something

In your .bashrc or .profile, add:

export PYTHONSTARTUP=$HOME/.env.py

What it does: When you login and open a terminal, the environment variable PYTHONSTARTUP will be set, and when you execute python (or bpython, too), the python interpreter will load whatever scripts are in PYTHONSTARTUP and be ready for you to use them without having to type them everytime. In this example, I could use functionality something of some_module right away.


François
@f_dion

2013 Raspberry Pi Python Adventures Review

More work, less social media

2013 kept me quite busy. I worked hard on Dion Research doing digital signage and interfacing with manufacturing equipment. I also took on a new position doing more Python development. And increased quite a bit the number of social events in the local Python community (actual physical events). What this means is that social media interaction slowed down some. This was even worse in the other languages, such as french, spanish and portuguese. The output there was quite spotty. Still, some of the articles and tweets I posted in 2013 were quite popular.

Most Popular

Hardware hacking and Python in the browser were the 2 most popular themes. In fact, in the #1 spot by far in terms of views in 2013 was an article on Brython from December 2012:

http://raspberry-python.blogspot.com/2012/12/brython-browser-python.html

Now, a year later, Brython has been through many changes, including more javascript compatibility (and ongoing restructuring). You can learn more by checking out the Brython documentation.

Soliloquy: I spent a few weeks preparing something on Brython for PyCon, but the talk didn't get accepted, unfortunately, and has left me a bit ambivalent about conferences: Is my time better served building elaborate talks on open source projects I contribute to, for conferences I may not get invited to? Or spending the time on the actual projects coding, or even on this blog?

But not all is a loss for you, the reader, since I'll post some of that material on this blog in the coming months.

The #2 was this article on making your own GPIO cable for the still very popular Raspberry Pi:

http://raspberry-python.blogspot.com/2013/02/making-your-own-raspberrypi-gpio-cable.html


Completing the podium at #3 for 2013 was:

http://raspberry-python.blogspot.com/2013/01/pyhacking-step-by-step.html

Least Popular

The least popular articles were all administrative in nature, such as the announcement of the addition of a contact form. It is clear that very few are interested in these kinds of posts, and they will continue to stay at a minimum for 2014.

2014

I just started yesterday a PTOT[D, W, M] (Python Tip Of The Day, Week, Month...). I'm curious to see how popular that will turn out to be. I'll also be introducing something new to help Windows users to get the most out of Python. Still, I recommend to get yourself a Raspberry Pi running Linux as a sidekick to your Windows machine, you'll be happier that way.

I'm also thinking about covering web.database, browser.local_storage, sqlalchemy, alembic and a few other database related themes.




What are some of the themes you'd like to hear about?


François
@f_dion

Python Tip of the [day, week, month]

PTOTD

Starting tomorrow, I'll post a Python tip on a regular basis. I cant promise a PTOTD, but it'll be more often than once a month, so that identifies the boundaries.

Ok, I lied, I'll start with one right now:

Tip #1

python -i script.py

What it does: At the conclusion of the execution of script.py, instead of exiting, the python interpreter stays in interactive mode, with everything ready to be printed or debugged.

François
@f_dion

Project Night: A red Raspberry Pi, 126 LEDs and a job

Project night

Every month, through PYPTUG, we set aside 2 nights for the Pythonistas and Pythonistas to be of the Piedmont Triad community. Tomorrow (wednesday the 20th of November) is one such night.

So what do we do there? The meetup page says:

"Do you have a project you want to show off? Or do you need a second set of eyes on your code? Would you like to hack on an open source project? Perhaps you need help getting a module on a specific platform? Don't have a project but would like to help others or to learn more Python?
Whatever the case may be, project nights are your opportunity to get some help or to help others, so bring your laptop (or Raspberry Pi or whatever device that can run Python) and let's get things going."

Red Raspberry Pi

So, I always show up at these project nights with a few potential projects. For example, hacking on Brython, or writing a good music collection manager in Python, or playing with a red Raspberry Pi. Red? Yes, this kind:

 

Pi Lite

But that wouldn't be a project in itself. I'll bring over a Pi Lite. What is that?


126 ways to have fun.

Spectrum analyzer? network traffic display? game of life? cool scroller? Who knows what i'll end up doing, but it'll be fun, I'm sure.

A job?

Oh yes, almost forgot. So this project night is in Winston Salem:

Inmar 2650 Pilgrim Court, Winston Salem, nc

And it just happen to be that there are some openings for Python developpers, doing web services and focusing on Python. If that sounds like fun, get in touch.

Winston Salem is a great place to live and work (and that's me saying this, coming from cosmopolitan Montreal). Plus Inmar is migrating downtown pretty soon, in the Wake Forest Innovation Quarter. So come on, take the first step and possibly come and join me and other enthusiastic Pythonistas at Inmar and drop me a note, or even better, email me your resume.

Requirements:
Experience with Python (web services a plus) and with Postgresql (or even mysql).

François
@f_dion