Python 3.6.5 Documentation >  "unicodedata" — Unicode Database

"unicodedata" — Unicode Database
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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
9.0.0.

The module uses the same names and symbols as defined by Unicode
Standard Annex #44, “Unicode Character Database”. It defines the
following functions:

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.

Changed in version 3.3: Support for name aliases [1] and named
sequences [2] has been added.

unicodedata.name(chr[, default])

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.

unicodedata.decimal(chr[, default])

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.

unicodedata.digit(chr[, default])

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.numeric(chr[, default])

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.category(chr)

Returns the general category assigned to the character *chr* as
string.

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.

unicodedata.combining(chr)

Returns the canonical combining class assigned to the character
*chr* as integer. Returns "0" if no combining class is defined.

unicodedata.east_asian_width(chr)

Returns the east asian width assigned to the character *chr* as
string.

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.

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.

unicodedata.normalize(form, unistr)

Return the normal form *form* for the Unicode string *unistr*.
Valid values for *form* are ‘NFC’, ‘NFKC’, ‘NFD’, and ‘NFKD’.

The Unicode standard defines various normalization forms of a
Unicode string, based on the definition of canonical equivalence
and compatibility equivalence. In Unicode, several characters can
be expressed in various way. For example, the character U+00C7
(LATIN CAPITAL LETTER C WITH CEDILLA) can also be expressed as the
sequence U+0043 (LATIN CAPITAL LETTER C) U+0327 (COMBINING
CEDILLA).

For each character, there are two normal forms: normal form C and
normal form D. Normal form D (NFD) is also known as canonical
decomposition, and translates each character into its decomposed
form. Normal form C (NFC) first applies a canonical decomposition,
then composes pre-combined characters again.

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
(e.g. gb2312).

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

Even if two unicode strings are normalized and look the same to a
human reader, if one has combining characters and the other
doesn’t, they may not compare equal.

In addition, the module exposes the following constant:

unicodedata.unidata_version

The version of the Unicode database used in this module.

unicodedata.ucd_3_2_0

This is an object that has the same methods as the entire module,
but uses the Unicode database version 3.2 instead, for applications
that require this specific version of the Unicode database (such as
IDNA).

Examples:

>>> import unicodedata
>>> unicodedata.lookup('LEFT CURLY BRACKET')
'{'
>>> unicodedata.name('/')
'SOLIDUS'
>>> unicodedata.decimal('9')
9
>>> unicodedata.decimal('a')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: not a decimal
>>> unicodedata.category('A') # 'L'etter, 'u'ppercase
'Lu'
>>> unicodedata.bidirectional('\u0660') # 'A'rabic, 'N'umber
'AN'

-[ Footnotes ]-

[1] http://www.unicode.org/Public/9.0.0/ucd/NameAliases.txt

[2] http://www.unicode.org/Public/9.0.0/ucd/NamedSequences.txt