python bytes 和 str的互转

# bytes object  
 b = b"example"  

 # str object  
 s = "example"  

 # str to bytes  
 bytes(s, encoding = "utf8")  

 # bytes to str  
 str(b, encoding = "utf-8")  

 # an alternative method  
 # str to bytes  
 str.encode(s)  

 # bytes to str  
 bytes.decode(b)