regex match either string in linux "find" command - regex

Question

I'm trying the following to recursively look for files ending in either .py or .py.server:
$ find -name "stub*.py(|\.server)"
However this does not work.
I've tried variations like:
$ find -name "stub*.(py|py\.server)"
They do not work either.
A simple find -name "*.py" does work so how come this regex does not?

Answer 1

Say:
find . \( -name "*.py" -o -name "*.py.server" \)
Saying so would result in file names matching *.py and *.py.server.
From man find:
expr1 -o expr2
Or; expr2 is not evaluated if expr1 is true.
EDIT: If you want to specify a regex, use the -regex option:
find . -type f -regex ".*\.\(py\|py\.server\)"

Answer 2

Find can take a regular expression pattern:
$ find . -regextype posix-extended -regex '.*[.]py([.]server)?$' -print
Options:
-regex pattern
File name matches regular expression pattern. This is a match on the whole path, not a search. For example, to match a file named ./fubar3, you can use the regular expression .*bar. or
.*b.*3, but not f.*r3. The regular expressions understood by find are by default Emacs
Regular Expressions, but this can be changed with the -regextype option.
-print True;
print the full file name on the standard output, followed by a newline. If you are piping
the output of find into another program and there is the faintest possibility that the files which
you are searching for might contain a newline, then you should seriously consider using the
-print0 option instead of -print. See the UNUSUAL FILENAMES section for information about how
unusual characters in filenames are handled.
-regextype type
Changes the regular expression syntax understood by -regex and -iregex tests which occur later on
the command line. Currently-implemented types are emacs (this is the default), posix-awk, posix-
basic, posix-egrep and posix-extended.
A clearer description or the options. Don't forgot all the information can be found by reading man find or info find.

Answer 3

find -name does not use regexp, here's an extract from the man page on Ubuntu 12.04
-name pattern
Base of file name (the path with the leading directories
removed) matches shell pattern pattern. The metacharacters
(`*', `?', and `[]') match a `.' at the start of the base name
(this is a change in findutils-4.2.2; see section STANDARDS CON‐
FORMANCE below). To ignore a directory and the files under it,
use -prune; see an example in the description of -path. Braces
are not recognised as being special, despite the fact that some
shells including Bash imbue braces with a special meaning in
shell patterns. The filename matching is performed with the use
of the fnmatch(3) library function. Don't forget to enclose
the pattern in quotes in order to protect it from expansion by
the shell.
So the pattern that -name takes is more like a shell glob and not at all like a regexp
If I wanted to find by regexp I'd do something like
find . -type f -print | egrep 'stub(\.py|\.server)'