(Python) How to extract elements between parentheses from a spliced list-CodePudding

So I was doing a PEMDAS calculator and I managed to do everything but the parenthesis so my question is how to extract from a list like this : r = ["4"," ","2","(","2"," ","5",")"]

["2"," ","5"]

and to clarify it more if the code was like this: r = ["4"," ","2","(","2"," ","5",")"," ","(","2"," ","5",")"]

this should be the output ["2"," ","5","2"," ","5"]

CodePudding user response：

you can use this code to extract data between parenthesis. so you have a list which contain the data you want.

r = ["4"," ","2","(","2"," ","5",")"]
r_new = []
for i in range(len(r)):
    if r[i] == "(":
        i=i 1
        for j in range(len(r)-i):
            if(r[i j]==")"):
                print(r_new)
                break
            else:
                r_new.append(r[i j])

CodePudding user response：

Will this be workable for you?

r = ['4', ' ', '2', '(', '2', ' ', '5', ')', ' ', '(', '2', ' ', '5', ')']

index = [x for x,y in enumerate(r) if y == '(' or y == ')']

grouped_index = [[index[i*2],index[i*2 1]] for i in range(int(len(index)/2))]

grouped_value = [r[i[0] 1:i[1]] for i in grouped_index]

sum(grouped_value, [])

['2', ' ', '5', '2', ' ', '5']