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Python 3.5 Brings New Language Features and Library Modules

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Recently released Python 3.5 brings a host of changes, including several new syntax features, new library modules, improvements to the standard library, and to security.

Syntax features

Python 3.5 introduces three new syntactic features:

  • coroutines with async-await syntax, which allows developers to write code as if it were sequential. In fact, the compiler will implement it through a sequence of coroutines, thus making it effectively concurrent. In the following example, multiple await statements can be thought of as executing sequentially, but they would not cause any actual block:

    async def read_data(db):
    data = await db.fetch('SELECT ...')
    if (data...)
        await api.send(data ...')
    
  • a matrix multiplication operator that allows to express the multiplication between matrices as a @ b. This will allow to write:

    S = (H @ beta - r).T @ inv(H @ V @ H.T) @ (H @ beta - r)
    
    instead of:
    S = dot((dot(H, beta) - r).T, dot(inv(dot(dot(H, V), H.T)), dot(H, beta) - r))
    	
  • unpacking generalization, which is meant to extend the allowed usage of the * unpacking operator and make it possible to use it multiple times in function calls, or inside of tuples:

    >>> print(*[1], *[2], 3)
    1 2 3
    >>> dict(**{'x': 1}, y=2, **{'z': 3})
    {'x': 1, 'y': 2, 'z': 3}
    
    
    >>> *range(4), 4
    (0, 1, 2, 3, 4)
    

Library Modules

New library modules in Python 3.5 introduce:

  • type hints, which aim to enable type checking annotations to 3rd party modules while also allowing unaltered execution if desired.
  • new zipapp module provides an API and command line tool for creating executable Python Zip Applications.

Other changes brought by Python 3.5 include:

Additionally, SSLv3 has been disabled by default, although it can be enabled if required.

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