019-python functions and common modules-built-in functions, 019-python built-in

019-python functions and common modules-built-in functions, 019-python built-in

1 #1. abs absolute value 2 n = abs (-1) 3 print (n) 4 # output 5 1 6 7 #2. boolean value 8 #0, None ,"", [], () # The result is False 9 print (bool (0) 10 # output 11 False12 13 #3. True 14 n = all, 3, None]) 15 print (n) 16 # output 17 False18 19 n = all ([1, 2, 4]) 20 print (n) 21 # output 22 True23 24 #4. If there is truth, it will be true 25 n = any ([None, "", 1]) 26 print (n) 27 # output 28 True29 30 #5. Binary, octal, and hexadecimal 31 # bin () binary 32 # oct () Evaluate octal 33 # hex () hexadecimal 34 print (bin (5) 35 print (oct (9) 36 print (hex (15) 37 # output 38 0b10139 0o1140 0xf

1 # One UTF-8 character: Three bytes 2 # gbk one Chinese Character: two bytes 3 # UTF-8 4 s = "Li Jie" 5 # one byte 8 bits, one Chinese character three bytes 6 # String Conversion byte type 7 # bytes (as long as the conversion string, according to what encoding) 8 n = bytes ("Li Jie", encoding = "UTF-8 ") 9 print (n) 10 n = bytes ("Li Jie", encoding = "gbk") 11 print (n) 12 13 # output 14 B '\ xe6 \ x9d \ x8e \ xe6 \ x9d \ xb0' # byte type, display in hexadecimal notation 15 B '\ xc0 \ xee \ xbd \ xdc'

1 # convert byte to string use str () function 2 new_str = str (bytes ("Li Jie", encoding = "UTF-8"), encoding = "UTF-8") 3 print (new_str) 4 # Why is the second encoding not decoding? 5 6 # output 7 Li Jie