Syntaxe de base
===============

Assignation de variables
------------------------

::

    >>> number = 10
    >>>  number
    10
    >>> name = 'Dupont'
    >>> name
    'Dupont'
    >>> a, b = 3, 5
    >>>a
    3
    >>>b
    5

Swap
----

::

    >>> a = 10
    >>> b = 20
    >>> a, b = b, a
    >>> a
    20
    >>> b
    10

Types de base
=============

-  chaines "John Doe"
-  nombres 1 3.8
-  listes [1, 4, 3, "John", variable
-  tuples (1, 4, 3, "John", variable)
-  dictionnaires { 'first\_name': 'John', 'last\_name': "Doe", 'age':
   25}

Strings
-------

::

    >>> last_name = 'Dupont'
    >>> first_name = "Jean"
    >>> full_name = '''jean dupont'''

Multilignes
~~~~~~~~~~~

::

    >>> long_str ="""une longue
    ... chaine
    ... de trois
    ... lignes"""
    >>> long_str
    'une longue\nchaine\nde trois\nlignes'
    >>> print long_str
    une longue
    chaine
    de trois
    lignes

Échappement
~~~~~~~~~~~~

::

    >>> school = 'ecole d\'ingenieur'
    >>> print school
    ecole d'ingenieur

Formatage de chaine
~~~~~~~~~~~~~~~~~~~

::

    >>> name = 'Joe'
    >>> print ('Salut {0}'.format(name))
    Salut Joe

    >>> print ('hello %s' % name)
    hello Joe

    >>> "{0} is easier than {1}".format("python", "java")
    'python is easier than java'

    >>>name= "Jim"
    >>> `Bonjour {name}, comment ça va ?`
    'Bonjour Jim, comment ça va ?

Nombres
-------

::

    >>> age = 10
    >>> price = 5.2

Incrémentation
~~~~~~~~~~~~~~

::

    >>> a+=1
    >>> a-=2

\*\* Attention à la précisions des flottants (cf IEE 754) *\** ##
Booléens >>> a = True >>> b = False

Réassigner
----------

::

    >>> a = 20
    >>> a = 'Dupont'

Noms de variables
-----------------

-  minuscules
-  underscores
-  != keywords python

Interdits

::

    >>> import keyword
    >>> print keyword.kwlist

Dangereux

::

    >>> dir(__builtins__)

Notamment: dict, file, id, list, str, type, sum

Variables en détail
-------------------

Les variables sont des étiquettes Obtenir l'id dune variable >>> id(a)
140654160195904

::

    >>> a= 10
    >>> id(a)
    140654160195952
    >>> c=a
    >>> id(c)
    140654160195952 # même id

Mutabilité
~~~~~~~~~~

::

    >>> a = 12
    >>> id(a)
    140654160195904 #id a changé

Le type
~~~~~~~

::

    >>> a = 10
    >>> type (a)
    <type 'int'>

Objets
------

Tout est objet

::

    >>> name ='toto'
    >>> name.capitalize()
    'Toto'

Obtenir les
----------

dir()

::

    >>> a = 5
    >>> dir (a)
    ['__abs__', '__add__', '__and__', '__class__', '__cmp__', '__coerce__', '__delattr__', '__div__', '__divmod__', '__doc__', '__float__', '__floordiv__', '__format__', '__getattribute__', '__getnewargs__', '__hash__', '__hex__', '__index__', '__init__', '__int__', '__invert__', '__long__', '__lshift__', '__mod__', '__mul__', '__neg__', '__new__', '__nonzero__', '__oct__', '__or__', '__pos__', '__pow__', '__radd__', '__rand__', '__rdiv__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rlshift__', '__rmod__', '__rmul__', '__ror__', '__rpow__', '__rrshift__', '__rshift__', '__rsub__', '__rtruediv__', '__rxor__', '__setattr__', '__sizeof__', '__str__', '__sub__', '__subclasshook__', '__truediv__', '__trunc__', '__xor__', 'bit_length', 'conjugate', 'denominator', 'imag', 'numerator', 'real']

help()

::

    >>> help(a)
    Help on int object:

    class int(object)
     |  int(x[, base]) -> integer
     |
     |  Convert a string or number to an integer, if possible.  A floating point
     |  argument will be truncated towards zero.....

String methods
--------------

::

    >>> name = 'john doe'
    >>> name.startswith('joh')
    True
    >>> name.startswith('josh')
    False
    >>> name.startswith(('john', 'bill'))
    True
    >>> 'doe' in name
    True

Listes
======

::

    >>> [1, 2, 3, 9, 'abc', 2.8, name ]
    >>> [1, 2, 3, 9, ['abc', 2.8, name] ]
    >>> l = [ 'a', 'b', 'c', 'd', 'e', 'f']

Indices

::

    >>> l[0]
    'a'
    >>> l[5]
    'f'
    >>> l[-1]
    'f'
    >>> l[-6]
    'a'

Slices

::

    >>> l[1:5]
    ['b', 'c', 'd', 'e']
    >>> l[:3]
    ['a', 'b', 'c']
    >>> l[:-2]
    ['a', 'b', 'c', 'd']

    >>> l[2] = "X"
    >>> l
    ['a', 'b', 'X', 'd', 'e', 'f']

Syntaxe : 

::

    seq = l[start:stop:step]


Copier une liste

::

    >>> other_list = l[:]
    >>> another_list = list(l)

Concaténation

::

    >>> k = ['q', 'r']
    >>> l+k
    ['a', 'b', 'c', 'd', 'e', 'f', 'q', 'r']

Ajout   

::

    >>> l = ['a', 'b']
    >>> l.append('c')
    ['a', 'b', 'c']

Tri

::

    >>> l = [4, 7, 9, 0]
    >>> l.sort()
    >>> l
    [0, 4, 7, 9]


Ordre

::

    >>> l.reverse()
    >>> l
    ['f', 'e', 'd', 'c', 'b', 'a']

Tuples
======

Listes immutables

::

    >>> t = (1, 2, 3)
    >>> t = tuple(l)
    >>> t
    ('a', 'b', 'c', 'd', 'e', 'f')
    >>> l = list(t)
    >>> l
    ['a', 'b', 'c', 'd', 'e', 'f']

constructeur = comma

::

    >>> t = (1)
    >>> t
    1
    >>> t = (1,)
    >>> t
    (1,)
    >>> t =1,
    >>> t
    (1,)
    >>> t =1, 2
    >>> t
    (1, 2)

Swap : ``a, b  = b, a``

Assignation : ``x, y = 1, 2``

Dictionnaires
=============

<=> Hashtable key: immutables (numbers, str, tuples) values: whatever

::

    >>> d = {'first_name' : 'john', 'last_name': 'doe'}
    >>> d['first_name']
    'john'
    >>> d['age']
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    KeyError: 'age'
    >>> d.get('age', 'Inconnu')
    'Inconnu'


Delete

::

    >>> del d['last_name']
    >>> d
    {'city': 'toulon', 'first_name': 'john'}

Méthodes utiles

::

    >>> d.keys()
    ['first_name', 'last_name']
    >>> d.values()
    ['john', 'doe']
    >>> d.items()
    [('first_name', 'john'), ('last_name', 'doe')]

 Licence: CC-BY Providenz