Structures de contrôle
======================

Algèbre booleenne standard
--------------------------

[],{}, 0, False, None -> False

==, !=, <, <=, >, >=

and, or

is
~~

is checke que les objets sont les mêmes 

::

    >>> a = 1 
    >>> b = 1 
    >>> a == b 
    True 
    >>> a is b 
    True 

mais

::

    >>> a = ["e"]
    >>> b = ["e"]
    >>> a==b
    True
    >>> a is b
    False

Branchements
------------

if
~~

::

    >>> if n == 10:
    ...     print 'dix'

Attention [], {}, 0 != None

::

    >>> if l != []: #pas bien
    >>> if l: #bien

    >>> if l == {}:
    >>> if not l:

    >>> if var is None:
    >>> if var is not None:

else
~~~~

::

    >>> if n == 10:
    ...     print 'dix'
    ... else:
    ...     print 'inf ou egal a 5'

elif
~~~~

::

    >>> if n > 5:
    ...     print 'sup a 5'
    ... elif n < 5:
    ...     print 'inf a 5'
    ... else:

assignation conditionnelle
~~~~~~~~~~~~~~~~~~~~~~~~~~

::

    >>> var = val1 if condition else val2

loop
----

for
~~~

::

    >>> for i in range(10):
        print i

Parcourir une liste
^^^^^^^^^^^^^^^^^^^

::

    >>> l = ['a', 'b', 'c']
    >>> for i in l:
    ...     print i
    ...
    a
    b
    c

avec index
^^^^^^^^^^

::

    >>> for index, value in enumerate(l):
    ...     print index, value
    ...
    0 a
    1 b
    2 c

ça marche avec les listes et les strings

sortie de loop
^^^^^^^^^^^^^^

::

    >>> for i in l:
    ...     print i
    ...     if i == 'b':
    ...             break
    ...
    a
    b

for .. else
^^^^^^^^^^^

::

    >>> for i in xrange(10):
    ...     if i == 20:
    ...             print '20'
    ...             break
    ... else:
    ...     print 'pas trouve'

loop sur plusieurs éléments
~~~~~~~~~~~~~~~~~~~~~~~~~~~

::

    >>> t = (('john', 'doe'), ('jean', 'dupont'), ('corinne', 'martin'))
    >>> for first_name, last_name in t:
    ...     print (first_name, last_name)
    ...
    ('john', 'doe')
    ('jean', 'dupont')
    ('corinne', 'martin')

loop sur dict
~~~~~~~~~~~~~

::

    d = {'city': 'toulon', 'first_name': 'john', 'last_name': 'doe'}
    >>> for k, v in d.items():
    ...     print (k, v)
    ...
    city toulon
    first_name john
    last_name doe

while
~~~~~

::

    >>> x = 1 
    >>> while x <= 5:
    ...     print x
    ...     x += 1
    ...
    1
    2
    3
    4
    5

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