You could use "|", which means "or":
0|1|2|3|4|5|6|7|8|9but as each of the alternatives is just a single character, there is a simpler way to write the same pattern:
You can use "[ ]" to mean "any character from this list" e.g.
[qwerty]would match (any line containing) either a "q" or a "w" or an "e" or an "r" or a "t" or a "y"
You can simplify things even more by using "-" to mean a range of characters e.g.
[a-e]is shorthand for
If you want to recognise any character (except newline), look here.