Extracting whole words

Question

I have a large set of real-world text that I need to pull words out of to input into a spell checker. I\'d like to extract as many meaningful words as possible with

Answer 1

If you restrict yourself to ASCII letters, then use (with the re.I option set)

\b[a-z]+\b

\b is a word boundary anchor, matching only at the start and end of alphanumeric "words". So \b[a-z]+\b matches pie, but not pie21 or 21pie.

To also allow other non-ASCII letters, you can use something like this:

\b[^\W\d_]+\b

which also allows accented characters etc. You may need to set the re.UNICODE option, especially when using Python 2, in order to allow the \w shorthand to match non-ASCII letters.

[^\W\d_] as a negated character class allows any alphanumeric character except for digits and underscore.