Why Python 3?

At the Institute we use both Python 2 and Python 3. While researching the current differences (Python 3.5, compared to Python 2.7), I found two beautiful articles by Brett Cannon, the current manager of Python, and summarized them for my work group.

The articles:

  1. Why Python 3: Why Python3 exists
  2. Why use 3: How to pitch Python 3 to Management

The relevant points for us1 are the following:

  1. Why Python 3 was necessary:

    • Python2: string = byte-array.
      • Py3 avoids Encoding-Bugs in Unicode: all Strings are Unicode.
    • Python2: sources in ASCII. β in a comment needed # encoding: utf-8
      • Py3 uses utf-8 in source files by default.
    • Last chance: the cost of the chance increased every year.
  2. Why use 3 (relevant for us, e.G. for new projects):

    • int/long -> int
    • Unicode in Code: σ = sqrt(var) # only letters, but i.e. not Σ
    • H.dot(β) -> H @ β
    • chained exceptions: Traceback ... during handling ... Traceback — simplifies debugging
    • print() facilitates structured output2

The effect of these points is much larger than this short text suggests: avoid surprises, avoid awkward workarounds, and easier debugging.


  1. I have summarized them because I can not expect scientists (or other people who only use Python) to read the full articles, just to decide what they do when they get the channce to tackle a new project. 

  2. Example for print():
    nums = [1, 2, 3]
    with open("data.csv", "a") as f:
        print(*nums, sep=";", file=f) 

Use Node:

⚙ Babcom is trying to load the comments ⚙

This textbox will disappear when the comments have been loaded.

If the box below shows an error-page, you need to install Freenet with the Sone-Plugin or set the node-path to your freenet node and click the Reload Comments button (or return).

If you see something like Invalid key: java.net.MalformedURLException: There is no @ in that URI! (Sone/search.html), you need to setup Sone and the Web of Trust

If you had Javascript enabled, you would see comments for this page instead of the Sone page of the sites author.

Note: To make a comment which isn’t a reply visible to others here, include a link to this site somewhere in the text of your comment. It will then show up here. To ensure that I get notified of your comment, also include my Sone-ID.

Link to this site and my Sone ID: sone://6~ZDYdvAgMoUfG6M5Kwi7SQqyS-gTcyFeaNN1Pf3FvY

This spam-resistant comment-field is made with babcom.

Inhalt abgleichen
Willkommen im Weltenwald!
((λ()'Dr.ArneBab))



Beliebte Inhalte

Draketo neu: Beiträge

Ein Würfel System

sn.1w6.org news