python點滴

1、print語句： 
print 'hello world!' 
print "hello world!" 
print 'hello %s!'%('world') 
2、流程控制： 
if: 
a = 1;b = 2 
if (a == b): 
  print 'a = b' 
elif (a > b): 
  print 'a > b' 
elif (a   print 'a elif (a   print 'a   print '$%$#$%' 
for each : 
array = [1,2,3,4] 
total = 0 
for i in array: 
  total +=i 
for i in array: 
  total +=i > 2 
  pass 
3、資料型態： 
鍊錶：array=[1,2,3,4] print array  result:[1,2,3,4] 
雜湊： 
print set ([11,2,2,2,2,2,5 列連列： 3,4,4]) result:set([1,2,3,4]) 
set1 = set([1,2,3,4,5]) set2 = set([1,2,3,4 ,6]) 
print set1-set2 result:set([5]) 
print set1&set2 result:set([1,2,3,4]) 
print set1|set2 result:set([1,2,3, 4,5,6]) 
字典： 
dict = {} 
dict['zs'] = 12 
dict['ls'] = 25 
dict['ww'] = 36 
for key inp. ): 
  print '%s%s'%(key,dict[key])  result:ww36 ls25 zs12 
4、檔案讀取： 
f = file("D:worka.txt","r") print f.read() 
f.close() #檔案流需要關閉 
with open ("D:worka.txt","r") as f: 
   print f.read() 
with open ("D:workb .txt","w") as f: 
   f.write("i am ok!")