Python: misc one-liners and snippets
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Formatted date to datetime object
=================================

.. code-block:: python

    import time, datetime
    timestring = "2005-09-01 12:30:09"
    time_format = "%Y-%m-%d %H:%M:%S"
    datetime.datetime.strptime(timestring, time_format)

Punycode URLs
=============

.. code-block:: python

    domain = '\xd8\xa7\xd9\x84\xd8\xa7\xd8\xb9\xd9\x84\xd9\x8a-\xd9\x84\xd9'\
        '\x84\xd8\xa7\xd8\xaa\xd8\xb5\xd8\xa7\xd9\x84\xd8\xa7\xd8\xaa.\xd9'\
        '\x82\xd8\xb7\xd8\xb1'
    domain_unicode = unicode(domain, "utf8")
    domain_idna = domain_unicode.encode("idna")

or

.. code-block:: python

    domain = u'\u0627\u0644\u0627\u0639\u0644\u064a-\u0644\u0644\u0627\u062a'\
        '\u0635\u0627\u0644\u0627\u062a.\u0642\u0637\u0631'
    domain_idna = domain.encode("idna")

Save Python shell history
=========================

To save all the commands history of the current Python shell, use the
readline_ module as follows:

.. code-block:: python

    import readline
    readline.write_history_file('/tmp/my-history-file')


.. _readline: http://docs.python.org/library/readline.html


Lazy property
=============

Like ``@property``, but lazy (the returned value will be cached in the object).

.. code-block:: python

    def lazy_property(fn):
        attr_name = '_lazy_' + fn.__name__

        def getter(self):
            if not hasattr(self, attr_name):
                setattr(self, attr_name, fn(self))
            return getattr(self, attr_name)

        def setter(self, value):
            setattr(self, attr_name, value)

        def deleter(self):
            delattr(self, attr_name)

        return property(fget=getter, fset=setter, fdel=deleter, doc=fn.__doc__)