python 类型转换总结

一、数字和字符串

>>> ord('a')           # ascii码
97
>>> chr(97)            
'a'
>>> 
>>> hex(16)            # 16进制数
'0x10'
>>> int('0x10', 16)
16
>>> 
>>> oct(16)            # 8进制数   
'0o20'
>>> int('0o20', 8)
16
>>> 
>>> bin(16)            # 2进制数
'0b10000'
>>> int('0b10000', 2)
16
>>>
>>> str(16)            # 10进制数
'16'
>>> int('16')
16
>>> str(5.5)           # 浮点数
'5.5'
>>> float('5.5')
5.5

二、字符串和bytes

>>> s = "美女，你好"
>>> b = a.encode('utf-8')
>>> b
b'xe7xbex8exe5xa5xb3xefxbcx8cxe4xbdxa0xe5xa5xbd'
>>> s_new = b.decode('utf-8')
>>> s_new
'美女，你好'

>>> s = "美女，你好"
>>> b = bytes(s, 'utf-8')
>>> b
b'xe7xbex8exe5xa5xb3xefxbcx8cxe4xbdxa0xe5xa5xbd'
>>> s_new = str(b, 'utf-8')
>>> s_new
'美女，你好'

三、bytes和bytearray

>>> b
b'xe7xbex8exe5xa5xb3xefxbcx8cxe4xbdxa0xe5xa5xbd'
>>> ba = bytearray(b)
>>> ba
bytearray(b'xe7xbex8exe5xa5xb3xefxbcx8cxe4xbdxa0xe5xa5xbd')
>>> b_new = bytes(ba)
>>> b_new
b'xe7xbex8exe5xa5xb3xefxbcx8cxe4xbdxa0xe5xa5xbd'

四、bytearray和字符串

>>> s = "世界，你好"
>>> ba = bytearray(s, 'utf-8')
>>> ba
bytearray(b'xe4xb8x96xe7x95x8cxefxbcx8cxe4xbdxa0xe5xa5xbd')
>>> s_new = str(ba, 'utf-8')
>>> s_new
'世界，你好'