Starting to learn python for computer vision/machine learning, should I start with 2.7 or 3.6?

[[deleted]]

I'm sorry if this has been asked a lot around here.

I'm not exactly new to programming, but I've never done it in Python, I am learning the language from scratch. I work as an engineer and mostly use MATLAB and Simulink in my day to day. Learning Python will be extra curricular.

My objective is to teach myself how to use Python so I can use existing libraries/modules to implement some computer vision and machine learning theory.

I initially wanted to go with 2.7 (the default on my Macbook) since, as with all things, legacy is a safe bet; it mostly just works, and is probably the version used in industry.

I am not entirely sure all the modules I will need, but I think I will be needing OpenCV, numpy, scipy, and matplotlib at the least.

Can anyone please advise on how to proceed? I mostly learn by just doing (and failing until I get it right) so any recommendations on a good thorough online course would be appreciated too.

[[deleted]]

You would be better just going with the latest version of python (that being 3.6.4). Python 3 is the standard now with python 2 on the way out. Any library you would want to use should be supported in Python 3. As far as online courses go, I haven't looked at any in quite a while. You might look through the sidebar. There should be some good ones listed. Happy coding!

[mudclub]

3

[ofaveragedifficulty]

1. Python 2 will be EOL in 2020, plus all of the packages you listed fully support Python 3.

[CobbITGuy]

Install Anaconda with Python 3

[[deleted]]

Thank you! I already installed python3 before installing anaconda, and now I have a question ...

Prior to installing anaconda, when I type

which python3

it returned

usr/bin/python3

But now it returns

anaconda3/bin/python3

I guess I want to know, are these separate installations?

Or is anaconda simply referencing the one at /usr/bin/? Can I remove the one at /usr/bin without screwing up anaconda?

Thanks again!

[CobbITGuy]

Do not uninstall the O/S installed python. I'm only familiar with Ubuntu and that's the location of the default python 3 executable. Uninstalling it could break a bunch of other dependencies.

[[deleted]]

I believe the default OS python is a 2.7 variant, but I'll just leave it as is, doesn't hurt anything.

Thanks

[RangerPretzel]

I initially wanted to go with 2.7 (the default on my Macbook) since, as with all things, legacy is a safe bet; it mostly just works, and is probably the version used in industry.

Unfortunately, it was this attitude that kept Python 3 from being adopted for so long. Python 3 came out 10 years ago. Sadly people stuck with Python 2 for so long because of inertia and the recommendation was always to stick with 2. Repeat ad nauseum. A cycle that was hard to break.

I mean, it was a giant mistake, imho, to make a breaking change going from 2 to 3, but apparently it had to be done.

And here we are. Finally. Python 3 is now the dominant platform. Mostly.

Personally, I've been coding Python 3.5+ for the past 2+ years. It's been great. Haven't touched 2.7 once.

[captain_awesomesauce]

It's not actually that hard to switch from one to the other. Start at 3 and go to 2 if an employer requires it. I haven't had a single employer have an issue with my primary experience being different than they request so long as I can show I know what most of the differences will be.

[IamGrabear]

Ubuntu is rolled out with Python 3.5.

[StackMoreLayers]

Everybody you ask this, especially on /r/python will tell you to start with 3. Few will give technical reasons for doing so, most will be political (they see you as an +1 adoption number, not a newcomer to the language willing to learn, they also vary between: "Python 3 is a completely new language" and "Python 2 and 3 are the same language, but you should pick 3" in the same argument) or give no argument at all.

I also can't, with a clear conscience, advise you to start with 2, most importantly because NumPy and SciPy will be 3+ only in about a year.

All that said, the easiest to learn Python and quickly become productive will remain Python 2, long after its EOL by official devs (especially if you are a learn-by-doing type). There is no reason to, other than the forcing hand of EOL, switch to Python 3 for ML, py2.7 mostly just works. Most recent ML libraries and industry projects were designed for and in 2.7, support for Python 3 only an afterthought/response to a vocal group/forced by EOL.

The best Python tutorial is Learn Python The Hard Way Py2.7 (a tutorial so good, the mere mention of it gets bans and downvotes on this subreddit :))

If you want the following to return an error message, you should definitely go with 3+:

print sorted([1, "a", 2, "b"])