didyoumean is a spelling-suggestion wrapper for pyhunspell designed to offer suggestions for misspelled words in search engine results, eg:

Did you mean: ... ?

didyoumean requires two things: pyhunspell, which, unfortunately, is not on PyPI, and Hunspell/MySpell dictionaries. The dictionaries can be installed via whatever package manager is available on your system.

Using pip:

pip install -e svn+http://pyhunspell.googlecode.com/svn/trunk/#egg=pyhunspell

In turn, pyhunspell requires hunspell, obviously.

All you need to do is create a DidYouMean object with the correct locale, then use the check() or suggest() methods.:

>>> d = DidYouMean('en-US')

>>> d.check('this sentence is correct')
True

>>> d.check('this sentence is worng')
False

>>> d.suggest('this sentence is worng')
[Word(old='this', new='this', corrected=False),
Word(old='sentence', new='sentence', corrected=False),
Word(old='is', new='is', corrected=False),
Word(old='worng', new='wrong', corrected=True)]

For each word in a sentence, suggest() returns a Word named tuple, with three properties: old (the original word), new (the new word), and corrected (a boolean, basically not old == new).

There is an optional dict_dir argument to DidYouMean() which tells it where to look for dictionary files. By default, it is /usr/share/myspell/. You should include a trailing slash.

You should always try to use a full locale (with country) when possible. didyoumean will fall back to just a language if it has to, but in many cases, only locale-specific dictionaries exist (like English).

For example, if I attempt to use the locale wx-YZ, didyoumean will do the following:

if wx_YZ dict exists
    use wx_YZ
else if wx dict exists
    use wx
else
    check() always returns True

If didyoumean can't find any dictionary, check() always returns true, and suggest() will always return words with no corrections. This is to avoid marking correctly spelled words as incorrect, just because a dictionary can't be found, and is motivated by the search engine use-case. (You do not want to offer spelling suggestions when you can't check spelling for a locale.)

Unfortunately, as far as I can tell, MySpell does not have a generic English dictionary. You need to specify en-US, en-GB, vel c. If you find a generic en dictionary, please let me know!

As with most spell-checks, didyoumean will not work on languages without separators between words. (I couldn't find dictionaries for Japanese or Chinese.) Since didyoumean works by checking each word individually, languages without word separators break.

• There is one failing test (in test_basic_farsi.py) which I believe is only failing because either I copied and pasted the text badly, or the suggestion doesn't match the expected text. In either case, if you speak Farsi and can fix the test case, please do!
• Once I incorporate this into our Django app, I'll include an example an example of how we use didyoumean. It will be specific to our app, ie: Django/Jingo/Jinja2, but hopefully demonstrate real-world usage.