Question

In python, I can use regular expression like this:

prog = re.compile(pattern)
result = prog.match(string)

And I can result.groups(0), result.groups(0), … etc.

How can I find out how many groups in the result? I tried ‘len(result.groups)’, but I get:

TypeError: object of type 'builtin_function_or_method' has no len()

Answer 1

What you are trying is correct but you just missed the parentheses:

Try:

len(result.groups())

That should do the work. As the error suggests, you are trying to get the length of a function. What you want is the length of the value (in this case, a tuple) returned after the execution of the function.