I've never used regular expressions before and I'm struggling to make sense of them. I have strings in the form of 'define(__arch64__)' and I just want the __arch64__.
import re
mystring = 'define(this_symbol)||define(that_symbol)'
pattern = 'define\(([a-zA-Z_]\w*)\)'
re.search(mystring, pattern).groups()
(None, None)
What doesn't search return 'this_symbol' and 'that_symbol'?
You have the parameters of search() in the wrong order, it should be:
re.search(pattern, mystring)
Also, backslashes are escape characters in python strings (for example "\n" will be a string containing a newline). If you want literal backslaches, like in the regular expression, you have to escape them with another backslash. Alternatively you can use raw strings that are marked by an r in front of them and don't treat backslashes as escape characters:
pattern = r'define\(([a-zA-Z_]\w*)\)'
\(, \) and \w aren't valid escape sequences in Python strings, so they didn't get replaced by anything else. But generally I'd recommend to use the r when dealing with strings that should contain backslashes.