List at least 5 differences between Python3 and Python2?
- print from statement to function
python2:print 1, 2+3
python3:: print ( 1, 2+3 )
- range 与 xrange
python2:range( 0, 4 ) 结果 是 列表 [0,1,2,3 ]
python3：list( range(0,4) )
python2 :xrange( 0, 4 ) 适用于 for 循环的变量控制
python3：range(0,4)
- String
python2: strings are stored as 8-bit strings
python3: Strings are stored as 16-bit Unicode strings
- Changes to the try except statement
python2:
try:
pass
except Exception, e :
pass
python3:
try:
pass
except Exception as e :
pass
- open a file
python2：file( ..... ) 或 open(.....)
python3：只能用 open(.....)
- Enter a string from the keyboard
python2: raw_input ("prompt information")
python3: input ("Prompt message")
- The bytes data type
bytes can be regarded as a "byte array" object, each element is an 8-bit byte, and the value range is 0 ~ 255.
Since the string is stored in unicode encoding in Python 3.0, when writing to a binary file, the string cannot be directly written (or read), and must be encoded as a sequence of bytes in some way before it can be written.
