\section{\module{unicodedata} ---         Unicode Database} \declaremodule{standard}{unicodedata}\modulesynopsis{Access the Unicode Database.}\moduleauthor{Marc-Andre Lemburg}{mal@lemburg.com}\sectionauthor{Marc-Andre Lemburg}{mal@lemburg.com}\sectionauthor{Martin v. L\"owis}{martin@v.loewis.de} \index{Unicode}\index{character}\indexii{Unicode}{database} This module provides access to the Unicode Character Database whichdefines character properties for all Unicode characters. The data inthis database is based on the \file{UnicodeData.txt} file version4.1.0 which is publicly available from \url{ftp://ftp.unicode.org/}. The module uses the same names and symbols as defined by theUnicodeData File Format 4.1.0 (see\url{http://www.unicode.org/Public/4.1.0/ucd/UCD.html}).  Itdefines the following functions: \begin{funcdesc}{lookup}{name}  Look up character by name.  If a character with the  given name is found, return the corresponding Unicode  character.  If not found, \exception{KeyError} is raised.\end{funcdesc} \begin{funcdesc}{name}{unichr\optional{, default}}  Returns the name assigned to the Unicode character  \var{unichr} as a string. If no name is defined,  \var{default} is returned, or, if not given,  \exception{ValueError} is raised.\end{funcdesc} \begin{funcdesc}{decimal}{unichr\optional{, default}}  Returns the decimal value assigned to the Unicode character  \var{unichr} as integer. If no such value is defined,  \var{default} is returned, or, if not given,  \exception{ValueError} is raised.\end{funcdesc} \begin{funcdesc}{digit}{unichr\optional{, default}}  Returns the digit value assigned to the Unicode character  \var{unichr} as integer. If no such value is defined,  \var{default} is returned, or, if not given,  \exception{ValueError} is raised.\end{funcdesc} \begin{funcdesc}{numeric}{unichr\optional{, default}}  Returns the numeric value assigned to the Unicode character  \var{unichr} as float. If no such value is defined, \var{default} is  returned, or, if not given, \exception{ValueError} is raised.\end{funcdesc} \begin{funcdesc}{category}{unichr}  Returns the general category assigned to the Unicode character  \var{unichr} as string.\end{funcdesc} \begin{funcdesc}{bidirectional}{unichr}  Returns the bidirectional category assigned to the Unicode character  \var{unichr} as string. If no such value is defined, an empty string  is returned.\end{funcdesc} \begin{funcdesc}{combining}{unichr}  Returns the canonical combining class assigned to the Unicode  character \var{unichr} as integer. Returns \code{0} if no combining  class is defined.\end{funcdesc} \begin{funcdesc}{east_asian_width}{unichr}  Returns the east asian width assigned to the Unicode character  \var{unichr} as string.\versionadded{2.4}\end{funcdesc} \begin{funcdesc}{mirrored}{unichr}  Returns the mirrored property assigned to the Unicode character  \var{unichr} as integer. Returns \code{1} if the character has been  identified as a ``mirrored'' character in bidirectional text,  \code{0} otherwise.\end{funcdesc} \begin{funcdesc}{decomposition}{unichr}  Returns the character decomposition mapping assigned to the Unicode  character \var{unichr} as string. An empty string is returned in case  no such mapping is defined.\end{funcdesc} \begin{funcdesc}{normalize}{form, unistr} Return the normal form \var{form} for the Unicode string \var{unistr}.Valid values for \var{form} are 'NFC', 'NFKC', 'NFD', and 'NFKD'. The Unicode standard defines various normalization forms of a Unicodestring, based on the definition of canonical equivalence andcompatibility equivalence. In Unicode, several characters can beexpressed in various way. For example, the character U+00C7 (LATINCAPITAL LETTER C WITH CEDILLA) can also be expressed as the sequenceU+0043 (LATIN CAPITAL LETTER C) U+0327 (COMBINING CEDILLA). For each character, there are two normal forms: normal form C andnormal form D. Normal form D (NFD) is also known as canonicaldecomposition, and translates each character into its decomposed form.Normal form C (NFC) first applies a canonical decomposition, thencomposes pre-combined characters again. In addition to these two forms, there are two additional normal formsbased on compatibility equivalence. In Unicode, certain characters aresupported which normally would be unified with other characters. Forexample, U+2160 (ROMAN NUMERAL ONE) is really the same thing as U+0049(LATIN CAPITAL LETTER I). However, it is supported in Unicode forcompatibility with existing character sets (e.g. gb2312). The normal form KD (NFKD) will apply the compatibility decomposition,i.e. replace all compatibility characters with their equivalents. Thenormal form KC (NFKC) first applies the compatibility decomposition,followed by the canonical composition. \versionadded{2.3}\end{funcdesc} In addition, the module exposes the following constant: \begin{datadesc}{unidata_version}The version of the Unicode database used in this module. \versionadded{2.3}\end{datadesc} \begin{datadesc}{ucd_3_2_0}This is an object that has the same methods as the entiremodule, but uses the Unicode database version 3.2 instead,for applications that require this specific version ofthe Unicode database (such as IDNA). \versionadded{2.5}\end{datadesc} Examples: \begin{verbatim}>>> unicodedata.lookup('LEFT CURLY BRACKET')u'{'>>> unicodedata.name(u'/')'SOLIDUS'>>> unicodedata.decimal(u'9')9>>> unicodedata.decimal(u'a')Traceback (most recent call last):  File "<stdin>", line 1, in ?ValueError: not a decimal>>> unicodedata.category(u'A')  # 'L'etter, 'u'ppercase'Lu'   >>> unicodedata.bidirectional(u'\u0660') # 'A'rabic, 'N'umber'AN'\end{verbatim}