python float轉int

http://cnblogs.com/dabiao/archive/2010/03/07/1680096.html

一、int函數能夠
     （1）把符合數學格式的數字型字符串轉換成整數
     （2）把浮點數轉換成整數，但是只是簡單的取整，而非四舍五入。

 

舉例：

 

           1 aa = int("124") #Correct 
          
 2  print "aa = ", aa #result=124 
          
 3  bb = int(123.45) #correct 
          
 4  print "bb = ", bb #result=123 
          
 5  cc = int("-123.45") #Error,Can't Convert to int 
          
 6  print "cc = ",cc 
          
 7 dd = int("34a") #Error,Can't Convert to int 
          
 8 print "dd = ",dd 
          
 9 ee = int("12.3") #Error,Can't Convert to int 
          
10 print ee 
          
11 
         

 

二、float函數將整數和字符串轉換成浮點數。

 

舉例：

 

           1 aa = float("124") #Correct 
          
 2 print "aa = ", aa #result = 124.0 
          
 3 bb = float("123.45") #Correct 
          
 4 print "bb = ", bb #result = 123.45 
          
 5 cc = float(-123.6) #Correct 
          
 6 print "cc = ",cc #result = -123.6 
          
 7 dd = float("-123.34") #Correct 
          
 8 print "dd = ",dd #result = -123.34 
          
 9 ee = float('123v') #Error,Can't Convert to float 
          
10 print ee 
         

 

 

三、str函數將數字轉換成字符

 

舉例：

 

           1 aa = str(123.4) #Correct 
          
 2 print aa #result = '123.4' 
          
 3 bb = str(-124.a) #SyntaxError: invalid syntax 
          
 4 print bb 
          
 5 cc = str("-123.45") #correct 
          
 6 print cc #result = '-123.45' 
          
 7 dd = str('ddd') #correct 
          
 8 print dd #result = ddd 
          
 9 ee = str(-124.3) #correct 
          
10 print ee #result = -124.3