Question

I have a list of strings that look like

"funcname(arg, another_arg)*20 + second_func(arg1, arg2)"

and I want to pull out just the args. I’ve tried the following:

re.findall(r'\w[\w\d_]+(?!\()', string)

however this returns

['funcnam', 'arg', 'another_arg', '20', 'second_fun', 'arg1', 'arg2']

Firstly, I’m a bit confused as to why I am seeing the '20', since I specified the string should start with a word character. Secondly, I’m wondering how I can improve my look-ahead to match what I’m looking for.

I should note that some of the strings don’t have functions and look like

"value1 + value_two"

so I can’t simply search inside the parentheses.

Answer 1

>>> pattern = '[a-zA-Z_]\w*(?![\(\w])'
>>> re.findall(pattern, "funcname(arg, another_arg)*20 + second_func(arg1, arg2)")
['arg', 'another_arg', 'arg1', 'arg2']
>>> re.findall(pattern, "value1 + value_two")
['value1', 'value_two']