# `unicodedata` --- Unicode データベース

This module provides access to the Unicode Character Database (UCD) which defines character properties for all Unicode characters. The data contained in this database is compiled from the UCD version 16.0.0.

このモジュールは、ユニコード標準付録 #44 「 ユニコード文字データベース 」で定義されているのと同じ名前およびシンボルを使用します。このモジュールは次のような関数を定義します:

参考

The Unicode HOWTO for more information about Unicode and how to use this module.

unicodedata.lookup(name)

  Look up character by name. If a character with the given name is found, return the corresponding character. If not found, `KeyError` is raised. For example:

      >>> unicodedata.lookup('LEFT CURLY BRACKET')
      '{'

  The characters returned by this function are the same as those produced by `\N` escape sequence in string literals. For example:

      >>> unicodedata.lookup('MIDDLE DOT') == '\N{MIDDLE DOT}'
      True

  バージョン 3.3 で変更: name aliases [1] と named sequences [2] のサポートが追加されました。

unicodedata.name(chr, default=None, /)

  Returns the name assigned to the character chr as a string. If no name is defined, default is returned, or, if not given, `ValueError` is raised. For example:

      >>> unicodedata.name('½')
      'VULGAR FRACTION ONE HALF'
      >>> unicodedata.name('\uFFFF', 'fallback')
      'fallback'

unicodedata.decimal(chr, default=None, /)

  Returns the decimal value assigned to the character chr as integer. If no such value is defined, default is returned, or, if not given, `ValueError` is raised. For example:

      >>> unicodedata.decimal('\N{ARABIC-INDIC DIGIT NINE}')
      9
      >>> unicodedata.decimal('\N{SUPERSCRIPT NINE}', -1)
      -1

unicodedata.digit(chr, default=None, /)

  Returns the digit value assigned to the character chr as integer. If no such value is defined, default is returned, or, if not given, `ValueError` is raised:

      >>> unicodedata.digit('\N{SUPERSCRIPT NINE}')
      9

unicodedata.numeric(chr, default=None, /)

  Returns the numeric value assigned to the character chr as float. If no such value is defined, default is returned, or, if not given, `ValueError` is raised:

      >>> unicodedata.numeric('½')
      0.5

unicodedata.category(chr)

  Returns the general category assigned to the character chr as string. General category names consist of two letters. See the General Category Values section of the Unicode Character Database documentation for a list of category codes. For example:

      >>> unicodedata.category('A')  # 'L'etter, 'u'ppercase
      'Lu'

unicodedata.bidirectional(chr)

  Returns the bidirectional class assigned to the character chr as string. If no such value is defined, an empty string is returned. See the Bidirectional Class Values section of the Unicode Character Database documentation for a list of bidirectional codes. For example:

      >>> unicodedata.bidirectional('\N{ARABIC-INDIC DIGIT SEVEN}') # 'A'rabic, 'N'umber
      'AN'

unicodedata.combining(chr)

  Returns the canonical combining class assigned to the character chr as integer. Returns `0` if no combining class is defined. See the Canonical Combining Class Values section of the Unicode Character Database for more information.

unicodedata.east_asian_width(chr)

  Returns the east asian width assigned to the character chr as string. For a list of widths and or more information, see the Unicode Standard Annex #11.

unicodedata.mirrored(chr)

  Returns the mirrored property assigned to the character chr as integer. Returns `1` if the character has been identified as a "mirrored" character in bidirectional text, `0` otherwise. For example:

      >>> unicodedata.mirrored('>')
      1

unicodedata.decomposition(chr)

  Returns the character decomposition mapping assigned to the character chr as string. An empty string is returned in case no such mapping is defined. For example:

      >>> unicodedata.decomposition('Ã')
      '0041 0303'

unicodedata.normalize(form, unistr)

  Unicode 文字列 unistr の正規形 form を返します。 form の有効な値は、'NFC'、'NFKC'、'NFD'、'NFKD' です。

  Unicode 規格は標準等価性 (canonical equivalence) と互換等価性 (compatibility equivalence) に基づいて、様々な Unicode文字列の正規形を定義します。Unicode では、複数の方法で表現できる文字があります。たとえば、文字 U+00C7 (LATIN CAPITAL LETTER C WITH CEDILLA) は、U+0043 (LATIN CAPITAL LETTER C) U+0327 (COMBINING CEDILLA) というシーケンスとしても表現できます。

  各文字には2つの正規形があり、それぞれ正規形 C と正規形 D といいます。正規形 D (NFD) は標準分解 (canonical decomposition) としても知られており、各文字を分解された形に変換します。正規形 C (NFC) は標準分解を適用した後、結合済文字を再構成します。

  In addition to these two forms, there are two additional normal forms based on compatibility equivalence. In Unicode, certain characters are supported which normally would be unified with other characters. For example, U+2160 (ROMAN NUMERAL ONE) is really the same thing as U+0049 (LATIN CAPITAL LETTER I). However, it is supported in Unicode for compatibility with existing character sets (for example, gb2312).

  The normal form KD (NFKD) will apply the compatibility decomposition, that is, replace all compatibility characters with their equivalents. The normal form KC (NFKC) first applies the compatibility decomposition, followed by the canonical composition.

  2つのunicode文字列が正規化されていて人間の目に同じに見えても、片方が結合文字を持っていてもう片方が持っていない場合、それらは完全に同じではありません。

unicodedata.is_normalized(form, unistr)

  Unicode 文字列 unistr が正規形 form かどうかを返します。 form の有効な値は、'NFC'、'NFKC'、'NFD'、'NFKD' です。

  Added in version 3.8.

更に、本モジュールは以下の定数を公開します:

unicodedata.unidata_version

  このモジュールで使われている Unicode データベースのバージョン。

unicodedata.ucd_3_2_0

  これはモジュール全体と同じメソッドを具えたオブジェクトですが、Unicode データベースバージョン 3.2 を代わりに使っており、この特定のバージョンの Unicode データベースを必要とするアプリケーション(IDNA など)のためものです。

脚注

[ 1 ]

https://www.unicode.org/Public/16.0.0/ucd/NameAliases.txt

[ 2 ]

https://www.unicode.org/Public/16.0.0/ucd/NamedSequences.txt