Modernize code to Python 3.6+ and some cleanup

04-text-byte/numerics_demo.py

@@ -7,12 +7,12 @@ re_digit = re.compile(r'\d')
 sample = '1\xbc\xb2\u0969\u136b\u216b\u2466\u2480\u3285'
 
 for char in sample:
-    print('U+%04x' % ord(char),                       # <1>
+    print(f'U+{ord(char):04x}',                       # <1>
           char.center(6),                             # <2>
           're_dig' if re_digit.match(char) else '-',  # <3>
           'isdig' if char.isdigit() else '-',         # <4>
           'isnum' if char.isnumeric() else '-',       # <5>
-          format(unicodedata.numeric(char), '5.2f'),  # <6>
+          f'{unicodedata.numeric(char):5.2f}',        # <6>
           unicodedata.name(char),                     # <7>
           sep='\t')
 # end::NUMERICS_DEMO[]