How to reveal Unicodes numeric value property

Question

\'\\u00BD\' # ½
\'\\u00B2\' # ²

I am trying to understand isdecimal() and isdigit() better, for this its necessary to understand unicode numeric va

Answer 1

To get the 'numeric value' contained in the character, you could use unicodedata.numeric() function:

>>> import unicodedata
>>> unicodedata.numeric('\u00BD')
0.5

Use the ord() function to get the integer codepoint, optionally in combination with format() to produce a hexadecimal value:

>>> ord('\u00BD')
189
>>> format(ord('\u00BD'), '04x')
'00bd'

You can get access to the character property with unicodedata.category(), which you'd then need to check against the documented categories:

>>> unicodedata('\u00DB')
'No'

where 'No' stands for Number, Other.

However, there are a series of .isnumeric() == True characters in the category Lo; the Python unicodedata database only gives you access to the general category and relies on str.isdigit(), str.isnumeric(), and unicodedata.digit(), unicodedata.numeric(), etc. methods to handle the additional categories.

If you want a precise list of all numeric Unicode characters, the canonical source is the Unicode database; a series of text files that define the whole of the standard. The DerivedNumericTypes.txt file (v. 6.3.0) gives you a 'view' on that database specific the numeric properties; it tells you at the top how the file is derived from other data files in the standard. Ditto for the DerivedNumericValues.txt file, listing the exact numeric value per codepoint.