Fred Drake | 28b2944 | 2000-06-13 20:50:50 +0000 | [diff] [blame] | 1 | \section{\module{unicodedata} --- |
| 2 | Unicode Database} |
| 3 | |
| 4 | \declaremodule{standard}{unicodedata} |
| 5 | \modulesynopsis{Access the Unicode Database.} |
| 6 | \moduleauthor{Marc-Andre Lemburg}{mal@lemburg.com} |
| 7 | \sectionauthor{Marc-Andre Lemburg}{mal@lemburg.com} |
Martin v. Löwis | 677bde2 | 2002-11-23 22:08:15 +0000 | [diff] [blame] | 8 | \sectionauthor{Martin v. L\"owis}{martin@v.loewis.de} |
Fred Drake | 28b2944 | 2000-06-13 20:50:50 +0000 | [diff] [blame] | 9 | |
| 10 | \index{Unicode} |
| 11 | \index{character} |
| 12 | \indexii{Unicode}{database} |
| 13 | |
| 14 | This module provides access to the Unicode Character Database which |
| 15 | defines character properties for all Unicode characters. The data in |
| 16 | this database is based on the \file{UnicodeData.txt} file version |
Martin v. Löwis | 677bde2 | 2002-11-23 22:08:15 +0000 | [diff] [blame] | 17 | 3.2.0 which is publically available from \url{ftp://ftp.unicode.org/}. |
Fred Drake | 28b2944 | 2000-06-13 20:50:50 +0000 | [diff] [blame] | 18 | |
| 19 | The module uses the same names and symbols as defined by the |
Martin v. Löwis | 677bde2 | 2002-11-23 22:08:15 +0000 | [diff] [blame] | 20 | UnicodeData File Format 3.2.0 (see |
Fred Drake | 6e1fecc | 2000-09-16 13:46:42 +0000 | [diff] [blame] | 21 | \url{http://www.unicode.org/Public/UNIDATA/UnicodeData.html}). It |
Fred Drake | 28b2944 | 2000-06-13 20:50:50 +0000 | [diff] [blame] | 22 | defines the following functions: |
| 23 | |
Fredrik Lundh | 0110d3b | 2001-01-24 08:10:07 +0000 | [diff] [blame] | 24 | \begin{funcdesc}{lookup}{name} |
| 25 | Look up character by name. If a character with the |
| 26 | given name is found, return the corresponding Unicode |
| 27 | character. If not found, \exception{KeyError} is raised. |
| 28 | \end{funcdesc} |
| 29 | |
| 30 | \begin{funcdesc}{name}{unichr\optional{, default}} |
| 31 | Returns the name assigned to the Unicode character |
| 32 | \var{unichr} as a string. If no name is defined, |
| 33 | \var{default} is returned, or, if not given, |
| 34 | \exception{ValueError} is raised. |
| 35 | \end{funcdesc} |
| 36 | |
Fred Drake | 28b2944 | 2000-06-13 20:50:50 +0000 | [diff] [blame] | 37 | \begin{funcdesc}{decimal}{unichr\optional{, default}} |
| 38 | Returns the decimal value assigned to the Unicode character |
| 39 | \var{unichr} as integer. If no such value is defined, |
| 40 | \var{default} is returned, or, if not given, |
| 41 | \exception{ValueError} is raised. |
| 42 | \end{funcdesc} |
| 43 | |
| 44 | \begin{funcdesc}{digit}{unichr\optional{, default}} |
| 45 | Returns the digit value assigned to the Unicode character |
| 46 | \var{unichr} as integer. If no such value is defined, |
| 47 | \var{default} is returned, or, if not given, |
| 48 | \exception{ValueError} is raised. |
| 49 | \end{funcdesc} |
| 50 | |
| 51 | \begin{funcdesc}{numeric}{unichr\optional{, default}} |
| 52 | Returns the numeric value assigned to the Unicode character |
| 53 | \var{unichr} as float. If no such value is defined, \var{default} is |
| 54 | returned, or, if not given, \exception{ValueError} is raised. |
| 55 | \end{funcdesc} |
| 56 | |
| 57 | \begin{funcdesc}{category}{unichr} |
| 58 | Returns the general category assigned to the Unicode character |
| 59 | \var{unichr} as string. |
| 60 | \end{funcdesc} |
| 61 | |
| 62 | \begin{funcdesc}{bidirectional}{unichr} |
| 63 | Returns the bidirectional category assigned to the Unicode character |
| 64 | \var{unichr} as string. If no such value is defined, an empty string |
| 65 | is returned. |
| 66 | \end{funcdesc} |
| 67 | |
| 68 | \begin{funcdesc}{combining}{unichr} |
| 69 | Returns the canonical combining class assigned to the Unicode |
| 70 | character \var{unichr} as integer. Returns \code{0} if no combining |
| 71 | class is defined. |
| 72 | \end{funcdesc} |
| 73 | |
| 74 | \begin{funcdesc}{mirrored}{unichr} |
| 75 | Returns the mirrored property of assigned to the Unicode character |
| 76 | \var{unichr} as integer. Returns \code{1} if the character has been |
| 77 | identified as a ``mirrored'' character in bidirectional text, |
| 78 | \code{0} otherwise. |
| 79 | \end{funcdesc} |
| 80 | |
| 81 | \begin{funcdesc}{decomposition}{unichr} |
| 82 | Returns the character decomposition mapping assigned to the Unicode |
| 83 | character \var{unichr} as string. An empty string is returned in case |
| 84 | no such mapping is defined. |
| 85 | \end{funcdesc} |
Martin v. Löwis | 677bde2 | 2002-11-23 22:08:15 +0000 | [diff] [blame] | 86 | |
| 87 | \begin{funcdesc}{normalize}{form, unistr} |
| 88 | |
| 89 | Return the normal form \var{form} for the Unicode string \var{unistr}. |
| 90 | Valid values for \var{form} are 'NFC', 'NFKC', 'NFD', and 'NFKD'. |
| 91 | |
| 92 | The Unicode standard defines various normalization forms of a Unicode |
| 93 | string, based on the definition of canonical equivalence and |
| 94 | compatibility equivalence. In Unicode, several characters can be |
| 95 | expressed in various way. For example, the character U+00C7 (LATIN |
| 96 | CAPITAL LETTER C WITH CEDILLA) can also be expressed as the sequence |
| 97 | U+0043 (LATIN CAPITAL LETTER C) U+0327 (COMBINING CEDILLA). |
| 98 | |
| 99 | For each character, there are two normal forms: normal form C and |
| 100 | normal form D. Normal form D (NFD) is also known as canonical |
| 101 | decomposition, and translates each character into its decomposed form. |
| 102 | Normal form C (NFC) first applies a canonical decomposition, then |
| 103 | composes pre-combined characters again. |
| 104 | |
| 105 | In addition to these two forms, there two additional normal forms |
| 106 | based on compatibility equivalence. In Unicode, certain characters are |
| 107 | supported which normally would be unified with other characters. For |
| 108 | example, U+2160 (ROMAN NUMERAL ONE) is really the same thing as U+0049 |
| 109 | (LATIN CAPITAL LETTER I). However, it is supported in Unicode for |
| 110 | compatibility with existing character sets (e.g. gb2312). |
| 111 | |
| 112 | The normal form KD (NFKD) will apply the compatibility decomposition, |
| 113 | i.e. replace all compatibility characters with their equivalents. The |
| 114 | normal form KC (NFKC) first applies the compatibility decomposition, |
| 115 | followed by the canonical composition. |
| 116 | |
| 117 | \versionadded{2.3} |
| 118 | \end{funcdesc} |
| 119 | |
Martin v. Löwis | b5c980b | 2002-11-25 09:13:37 +0000 | [diff] [blame] | 120 | In addition, the module exposes the following constant: |
| 121 | |
| 122 | \begin{datadesc}{unidata_version} |
| 123 | The version of the Unicode database used in this module. |
| 124 | |
| 125 | \versionadded{2.3} |
| 126 | \end{datadesc} |