alvesjnr

Lecture about the book Gödel Escher Bach

This is a short resume about what I understood about the masterpiece GEB, from Douglas Hofstadter

What is this book about?

"How do we get I's from None I's?"

alvesjnr

import sqlalchemy
engine = sqlalchemy.create_engine('sqlite:///:memory:', echo=False)
from sqlalchemy.ext.declarative import declarative_base
from Crypto.Hash import SHA256
from sqlalchemy.orm import relationship, backref

Base = declarative_base()

class User(Base):
    

alvesjnr

I got trapped by a lambda function

I consider myself a medium-to-experienced Python programmer (I am using python for 6 years). Today I've lost almos one hour in a very stupid bug with lambda functions. See what happend:

Tkinter, Buttons and Callbacks

I was building a very simple Tkinter GUI (I'm not an GUI expert, so I code in Tkinter because it is easy and simple, but I myself think that it is ugly).

alvesjnr

How does an spirograph work?

Some of you shall ask yourselves: "How does a spirograph work?". But I'm sure that most of you would ask me: "What the wacko is an spirograph?"

An spirograph is a toy used to draw "weird spirals" using two circles (one inside other). For whom doesn't remember, the toy is these one:

The way that this toy works is simples: One gear spins inside a big circle (also with gears!). The pen is placed in a hole of the gear. When you spin the gear through the major circle, the pen follows tho different movements: An circle movement made by the gear around the center of the great circle (let's call this point as O) and a movement made by the pen around the center of the gear (let's call the center of the gear as C and the point where the pen is placed as P). As the center of the gear is moving, the result position of the point P is the sum of these two movements: P over C

alvesjnr

Como os Espirógrafos Funcionam?

Alguns de vocês devem se perguntar: "Como os espirógrafos funcionam?". Mas a maioria de vocês perguntaria antes "espiro-o-que??".

Bem, espirógrafo é aquele brinquedo que muitos de nós usamos quando pequenos para fazer umas "espirais malucas" desenhadas no papel. O brinquedo é esse aí:

A mecânica do brinquedo é bem simples: uma roda dentada gira dentro de um círculo (também dentado). Sua caneta, que está presa em um orifíco da roda dentada acompanha dois movimentos distintos que são somados: o movimento circular em torno do ponto central do grande cículo (vamos chamar este ponto de O) e um movimento circular em torno do centro da roda dentada (vamos chamar o centro da roda dentada de C). Este centro, por sua vez, está em movimento. É a soma destes dois movimentos que faz surgir aqueles "desenhos muito doidos de São Tomé".

alvesjnr

Como os Espirógrafos Funcionam?

Alguns de vocês devem se perguntar: "Como os espirógrafos funcionam?". Mas a maioria de vocês perguntaria antes "espiro-o-que??".

Bem, espirógrafo é aquele brinquedo que muitos de nós usamos quando pequenos para fazer umas "espirais malucas" desenhadas no papel. O brinquedo é esse aí:

alvesjnr

from time import strftime
import Tkinter


numbers = {0:'midnight',
           1:'one',
           2:'two',
           3:'three',
           4:'four',

alvesjnr

#coding: utf-8

"""
    Conway's Game of Life implementation with console interface
    Author: Antonio Ribeiro - alvesjunior.antonio@gmail.com
    license: Do What You Want to
"""

from time import sleep
from random import randint

alvesjnr

root@d2b55f66d8dd:/srv/jupyterhub_config# cd /tmp/luceda-packages/
root@d2b55f66d8dd:/tmp/luceda-packages# ls
ipkiss-311-packages-linux64  luceda_cst-0.1.2-py27_1.tar.bz2
root@d2b55f66d8dd:/tmp/luceda-packages# . activate py2
(py2) root@d2b55f66d8dd:/tmp/luceda-packages# conda install -n py2 luceda_cst-0.1.2-py27_1.tar.bz2 
(py2) root@d2b55f66d8dd:/tmp/luceda-packages# python
Python 2.7.12 | packaged by conda-forge | (default, Sep  8 2016, 14:22:31) 
[GCC 4.8.2 20140120 (Red Hat 4.8.2-15)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from luceda_cst.model import CapheModelCST

alvesjnr

[D 2017-02-23 11:33:11.390 JupyterHub app:740] Generating new cookie_secret
[I 2017-02-23 11:33:11.390 JupyterHub app:745] Writing cookie_secret to /srv/jupyterhub_config/jupyterhub_cookie_secret
[D 2017-02-23 11:33:11.391 JupyterHub app:796] Connecting to db: sqlite:///jupyterhub.sqlite
[W 2017-02-23 11:33:12.361 JupyterHub app:365] 
    Generating CONFIGPROXY_AUTH_TOKEN. Restarting the Hub will require restarting the proxy.
    Set CONFIGPROXY_AUTH_TOKEN env or JupyterHub.proxy_auth_token config to avoid this message.
    
[D 2017-02-23 11:33:12.595 JupyterHub app:1085] Loading state for juno from db
[D 2017-02-23 11:33:12.596 JupyterHub dockerspawner:348] Getting container 'jupyter-juno'
[E 2017-02-23 11:33:12.667 JupyterHub app:1527]