Continuando a série sobre o módulo asyncio do Python 3.4, vou apresentar as corotinas e como elas simplificam a escrita de nossos programas com o loop de eventos.

Modificamos também a chamada de execução da corotina, pois agora utilizamos loop.run_until_complete para iniciar nossa corotina principal. Aproveitamos para colocar tudo entre um try-finally para terminar a execução do loop corretamente (mesmo em caso de exceção). Perceba que no exemplo anterior, com call_soon, passamos a função e seus parâmetros, mas não executamos a função em si. No caso de run_until_complete, estamos passando o retorno da chamada de print_and_repeat que é uma corotina, uma vez que a marcamos com o decorador @asyncio.coroutine.

Continuando a série sobre o módulo asyncio do Python 3.4, vou apresentar as corotinas e como elas simplificam a escrita de nossos programas com o loop de eventos.

Modificamos também a chamada de execução da corotina, pois agora utilizamos loop.run_until_complete para iniciar nossa corotina principal. Aproveitamos para colocar tudo entre um try-finally para terminar a execução do loop corretamente (mesmo em caso de exceção). Perceba que no exemplo anterior, com call_soon, passamos a função e seus parâmetros, mas não executamos a função em si. No caso de run_until_complete, estamos passando o retorno da chamada de print_and_repeat que é uma corotina, uma vez que a marcamos com o decorador @asyncio.coroutine.

With the release of Python 3.4, I updated my book on Introduction to Programming with Python. Some topics fall outside the scope of the book, which is intended for beginners. I’m going to start writing a series of short posts about some interesting topics that I think are worth discussing and might even be the basis for a new book.

One of the new features in Python 3.4 is the asyncio module, which brings various routines for calling asynchronous methods in Python. Asynchronous programming is a bit different from what we’re used to writing in Python, but it’s an excellent alternative to using threads and a good choice for solving problems with many inputs or outputs (I/O).

With the release of Python 3.4, I updated my book on Introduction to Programming with Python. Some topics fall outside the scope of the book, which is intended for beginners. I’m going to start writing a series of short posts about some interesting topics that I think are worth discussing and might even be the basis for a new book.

One of the new features in Python 3.4 is the asyncio module, which brings various routines for calling asynchronous methods in Python. Asynchronous programming is a bit different from what we’re used to writing in Python, but it’s an excellent alternative to using threads and a good choice for solving problems with many inputs or outputs (I/O).

Preparation

On July 30, I received my first Raspberry Pi, purchased at Element 14. After a one-month wait, it arrived in the mail, albeit late from Belgium – 9 pm. In reality, it arrived around lunchtime, but since I wasn’t home, the postman left it as regular mail.

The box is small, like a credit card. In fact, I found the computer amidst other letters.

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Preparation

On July 30, I received my first Raspberry Pi, purchased at Element 14. After a one-month wait, it arrived in the mail, albeit late from Belgium – 9 pm. In reality, it arrived around lunchtime, but since I wasn’t home, the postman left it as regular mail.

The box is small, like a credit card. In fact, I found the computer amidst other letters.

[]

Continuation of the post, originally made in the Python-Brasil list:

I’ll try again, as the thread has already discussed three different things:

1. Code to use in Python programs: why UTF-8 is highly recommended
2. Encodings in general and problems caused and solved by it
3. A bug in Python on Windows, when the prompt is set to page 65001

I’ll try to explain for everyone, as it’s a recurring topic.

But before getting back to these topics, we have to go back to files.

Continuation of the post, originally made in the Python-Brasil list:

I’ll try again, as the thread has already discussed three different things:

1. Code to use in Python programs: why UTF-8 is highly recommended
2. Encodings in general and problems caused and solved by it
3. A bug in Python on Windows, when the prompt is set to page 65001

I’ll try to explain for everyone, as it’s a recurring topic.

But before getting back to these topics, we have to go back to files.

A fellow blogger on Python-Brasil:

The colleagues have already talked about why UTF-8.

I just want to remind that the subject is more complicated than it seems, for example in Python 2.7:

# -*- coding: utf-8 -*-
print "Accents: áéíóúãõç"
print u"Accents2: áéíóúãõç"

Run the program above on Windows, either through IDLE or console:

C:\Users\nilo\Desktop>\Python27\python.exe test.py
Accents: ├í├®├¡├│├║├º├ú├Á
Accents2: áéíóúçãõ

You should have obtained good results only on the Accents2 line. If the string is not marked with unicode, it will be simply printed as a sequence of bytes, without translation. If you have u in front, like in accents2, Python gets that it needs to translate from unicode to cp850, in this case of console here at home. Already on Linux, both lines produce correct results!

A fellow blogger on Python-Brasil:

The colleagues have already talked about why UTF-8.

I just want to remind that the subject is more complicated than it seems, for example in Python 2.7:

# -*- coding: utf-8 -*-
print "Accents: áéíóúãõç"
print u"Accents2: áéíóúãõç"

Run the program above on Windows, either through IDLE or console:

C:\Users\nilo\Desktop>\Python27\python.exe test.py
Accents: ├í├®├¡├│├║├º├ú├Á
Accents2: áéíóúçãõ

You should have obtained good results only on the Accents2 line. If the string is not marked with unicode, it will be simply printed as a sequence of bytes, without translation. If you have u in front, like in accents2, Python gets that it needs to translate from unicode to cp850, in this case of console here at home. Already on Linux, both lines produce correct results!