ASCII ord() chr()

1. ord() 和chr(), unichr()相反

   ord('A') : ‘A ‘ —> 65

   ord(u'\u2020') : return 8224

   chr(65) : 65 —> A

2. ASCII code for ‘A’ is 65, ‘a’ is 97

>>> ord('A')
65

>>> ord('a')
97

>>> chr(65)
'A'

>>> chr(97)
'a'

3. Note:

   if {A:1, B:2, ….}

   ord('A')-64

   注意最开始A为65，如果设定A为1，则 - 64