namedentities 1.6.5

Easy conversion between Unicode characters and HTML entities (named, decimal, or hex)

When reading HTML, named entities are often neater and easier to comprehend than numeric entities, Unicode (or other charset) characters, or a mixture of all of the above. The ⊕ character, for example, is easier to recognize and remember as ⊕ than ⊕ or ⊕ or \u2295.

Because they fall within the ASCII range, entities are also much safer to use in multiple contexts than Unicode and its various encodings (UTF-8 and such).

This module helps convert from whatever characters or entities you have into named HTML entities. If you prefer entities of the counting type, it will render those (either decimal or hexadecimal). Or, if you prefer, it will help you go the other way, mapping all entities into Unicode. B

Usage

Python 2:

from namedentities import *

u = u'both em\u2014and–dashes…'

print "named:  ", repr(named_entities(u))
print "numeric:", repr(numeric_entities(u))
print "hex:"   ", repr(hex_entities(u))
print "unicode:", repr(unicode_entities(u))

yields:

named:   'both em—and–dashes…'
numeric: 'both em—and–dashes…'
hex:     'both em—and–dashes…'
unicode: u'both em\u2014and\u2013dashes\u2026'

You can do just about the same thing in Python 3, but you have to use a print function rather than a print statement, and prior to 3.3, you have to skip the u prefix that in Python 2 marks string literals as being Unicode literals. In Python 3.3 and following, however, you can start using the u marker again, if you like. While all Python 3 strings are Unicode, it helps with cross-version code compatibility. (You can use the six cross-version compatibility library, as the tests do.)

One good use for unicode_entities is to create cross-platform, cross-Python-version strings that conceptually contain Unicode characters, but spelled out as named (or numeric) HTML entities. For example:

unicode_entities('This ’thing” is great!')

This has the advantage of using only ASCII characters and common string encoding mechanisms, yet rendering full Unicode strings upon reconstitution. You can use the other functions, say named_entities(), to go from Unicode characters to named entities.

Alternate API

A new function entities(text, kind) takes text and the kind of entities you’d like returned. kind can be 'named' (the default), 'numeric', 'hex', 'unicode', or 'none'.

Encodings Akimbo

This module will help you map between HTML entities and Unicode characters, whichever style you prefer. It will not, however, specifically help you with “encodings” of Unicode characters such as UTF-8; for these, use the built-in decode string method (to get Unicode from UTF-8) and encode (to convert Unicode into UTF-8).

This is more an issue in Python 2, which makes Unicode a manual process. If you have (byte) strings containing UTF-8 (or other encoded) characters, please convert them to Unicode before processing with namedentities:

s = "String with some UTF-8 characters..."
print named_entities(s.decode("utf-8"))

Good advice for Python 2 is to convert data to full Unicode as soon as possible after reading it or otherwise ingesting it. Process in Unicode. Then encode back to UTF-8 etc. when you write the data out. This strategy is baked-in to Python 3, so needs to be less explicitly managed there.

Recent Changes

• 1.6.5 updates the testing matrix, packaging, and documentation. All vestiges of support for Python 2.5 and PyPy 1.9 and earlier are officially withdrawn; if you’re still back there, upgrade alredy!

• As of 1.6.4, decimal_entities() is a synonym for numeric_entities().

• As of 1.6.3, entities() raises a bespoke UnknownEntities class rather that KeyError if you request an unknown type of entities. More important, an old version of namedentities that was interfering with automated pip installations has been removed from PyPI.

• As of 1.6, entities() API added. A slightly different import mechanism is used.

• The numeric_entities(text) and hex_entities(text) APIs have been added, shifting the module’s mission from “named entities” to “general purpose entity transformation.” Live and learn!

• The unescape(text) API changes all entities into Unicode characters. While long present, is now available for easy external consumption. It has an alias, unicode_entities(text) for parallelism with the other APIs.

• Repackaged first as a Python package, rather than independent modules. Then, given my growing confidence in managing cross-version packages, previously separate backend implementations for Python 2 and Python 3 have been merged into a single backend.

• Automated multi-version testing managed with the wonderful pytest and tox. Successfully packaged for, and tested against, all late-model versions of Python: 2.6, 2.7, 3.2, 3.3, and 3.4, as well as PyPy 2.6.0 (based on 2.7.9) and PyPy3 2.4.0 (based on 3.2.5). Should run fine on Python 3.5, though py.test is broken on its pre-release iterations.

Notes

• Doesn’t attempt to encode <, >, or & (or their numerical equivalents) to avoid interfering with HTML escaping.

• This module started as basically a packaging of Ian Beck’s recipe. While it’s moved forward since then, it’s still mostly Ian under the covers. Thank you, Ian!

Installation

To install or upgrade to the latest version:

pip install -U namedentities

To easy_install under a specific Python version (3.3 in this example):

python3.3 -m easy_install --upgrade namedentities

(You may need to prefix these with sudo command to authorize installation. In environments without super-user privileges, you may want to use pip’s --user option, to install only for a single user, rather than system-wide.)