import re
import PyQt4 as pq
from lxml.html import *

i = 1
s1 = "bye"

i,s1 = 1,"bye"

s2 = "Bye "+s1+" world"
s2 = "Bye %s world"%s1
s2 = "Bye {0} world".format(s1)

+ - * / % **

x = 3
print x**4         # 81
print x%2          # 1

+ %
split rsplit join

str = "abc"
i = 3
print "%s%s%s"%(i,str,i)         # "3abc3"
 
str = "une phrase avec plein de mots dedans"
liste=str.split(' ')             # ['une', 'phrase', 'avec', 'plein', 'de', 'mots', 'dedans']
print ','.join(liste)            # une,phrase,avec,plein,de,mots,dedans

== != <  >  <= >=

or and not

min=x if x<y else y

=

 1: l1 = [1, 2.1, "trois"]
 2: print len(l1)                         # 3
 3:
 4: for i in l1:
 5:     print i,
 6:
 7: l1[1] = 4                             # → 1 4 trois
 8: print(l1[:1])                         # → [1]
 9: print(l1[1:])                         # → [4,'trois']
10:
11: l1.pop()                              # [1, 4]
12: l1.append(['trois',5])                # [1,4,['trois',5]]
13: l1.pop()                              # [1, 4]
14: l1.extend(['trois',5])                # [1,4,'trois',5]
15: del l1[0]                             # → [4,'trois',5]
16: l1.insert(0,"six")                    # → ['six',4,'trois',5]
17:
18: a,b,l3 = l1
19: ValueError: too many values to unpack
20: a,b,l3 = l1[0],l1[1],l1[2:]           # a → 'six', b → 4, l3 → ['trois',5]
21: l2 = [ "a",l1,"b" ]                   # → [ 'a', ['six', 4, 'trois', 5], 'b']

 1: T1 = ( 1, 4, "trois" )
 2: print(T1[:1])                         # (1,)
 3: print(T1[1:])                         # (4,'trois')
 4:
 5: # un tuple n'est pas une liste !
 6: T1[1]=2.1
 7: 'tuple' object does not support item assignment
 8: T1.pop()
 9: 'tuple' object has no attribute 'pop'

 1: h = {'z':1, 'y':"deux", 'x':3.0 }
 2: h[1] = 4                          # 'y':"deux", 'z':1 'x':3.0 1:4
 3: h['y'] = 2                        # 'y':2 'z':1 'x':3.0 1:4
 4: del h['z']                        # 'y':2 'x':3.0 1:4
 5: k = h.keys()                      # vue des clés : à ce moment de l'exécution → ['y', 'x', 1]
 6: v = h.values()                    # vue des valeurs : à ce moment de l'exécution → [2, 3.0, 4]
 7: for k in h.keys():
 8:     print "(%s->%s)"%(k,h[k]),
 9: # (y->2) (x->3.0) (1->4)

1: import re
2: s = " a = 5 "
3: if (re.search('^\s*\S+\s*=\s*\S+\s*$/',s):
4:     m=re.search('\s*(\S+)\s*=\s*(\S+)\s*$',s)
5:     x,y = m.group(1,2)        # x → "a", y → "5"
6:     s = re.sub('\s','',s)     # s → "a=5"
7:     h = re.findall('=+',s)    # h →  "="

Attention, il n'y a pas d'accolades pour séparer les blocs en python, c'est l'identation qui permet de les marquer. L'indentation fait partie de la syntaxe.

1: if ...:
2:     ...
3: elif ...:
4:     ...
5: else:
6:     ...

 1: while ...:
 2:     ...
 3:
 4: for i in liste:
 5:     ...
 6:
 7: for var in range(10):
 8:     ...
 9:
10: while ...:
11:     ...
12:     if ...:
13:         continue    # itération suivante
14:     elif ...:
15:         break        # fin des itérations

1: def f(a,b):
2:     ...
3: f(1.2,"tagada")

1: def f(p1,p2=[]):
2:     ...
3:
4: l1 = [1,2,3]
5: l2 = [4,5]
6: f([l1,l2])
7: # p1=[[1,2,3],[4,5]], p2=[]

1: def f(p1,p2=[]):
2:     ...
3:
4: l1 = [1,2,3]
5: l2 = [4,5]
6: f(l1,l2)
7: # p1=[1,2,3],p2=[4,5]]

1: def f():
2:     ...
3:     return -1
4:     ...    # ne sera pas exécuté
5:
6: i=f()        # $i → -1

1: import sys
2:
3: for line in sys.stdin:    # lit ligne à ligne
4:     print line,

 1: import re
 2:
 3: fh = open("/etc/passwd")
 4: for line in fh:
 5:     line=line.rstrip('\n')        # on enlève la fin de ligne
 6:     line=re.sub('#.*$','',line)    # on élimine les commentaires
 7:     if line=="":
 8:         break             # on passe les lignes vides
 9:     ...
10: fh.close()

1: fh = open("/tmp/toto","w")
2: i = 1
3: for item in liste:
4:     fh.write("%d: %s\n"%(i,item))
5:     i = i+1
6: fh.close()

s = """
bla bla
bla blabla bla
bla blabla blabla bla
"""

import os
os.system("ls -l /")

import subprocess
 
for i in subprocess.check_output(['/bin/ls','-l']).split('\n'):
    print i

try:
    des commandes...
except:
    afficher un message sympathique pour indiquer le problème

 1: # fichier Url.py
 2:
 3: import urllib
 4: class Url:
 5:
 6:   def __init__(self,uri):  #constructeur
 7:     self.uri=uri           #initialisation
 8:
 9:   def get(self):           #méthode
10:     print urllib.urlopen(self.uri).read()

1: from Url import *
2:
3: u = Url("http://www.insmi.fr")
4: u.get()

$Id: memopythoncore.txt 638 2012-05-23 07:06:18Z aicardi $