Custom function taking string as input which breaks a math problem into smaller bits and adds them to an array

user_6628874 0
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I have recently started learning python and am trying to build a simple function to break up a math problem into smaller parts. For example if the problem is (1+2)+(2+4) it would break it up and store it in an array: ["(1+2)", "+", "(2+4)"]. Below ill post the code i have so far.

code:

def crush(string):
    crushed_string = []
    for i in range(0, len(string)):
        current_problem = ""
        if string[i] == "(":
            for x in range(i, len(string)):
                if string[x] == ")":
                    for y in range(i, x+1):
                        current_problem += string[y]
                    print(current_problem)


string = "(1+2)+(3+4)"
crush(string)

I am printing current_problem to the terminal instead of adding it to an array just for testing but the output i am getting doesn't make sense to me... the output: (1+2) (1+2)(1+2)+(3+4) (3+4)

I'm not looking for a code dump but rather to understand what is happening and why so i can improve and not just copy paste. If anyone could please explain why this is the output i am getting i would be really grateful.

note: I know i haven't added the + between the brackets yet but I've ran into this problem before I've gotten to that and would like to first understand what is happening before moving on.

for-loop arrays python loops string
2 Answers

If you want to perform math operations into a string, the best solution is to use regular expressions like this. To learn more about them, please visit the official Python documentation about the re library :

import re

s = "(1+2)+(3+4)"
print(re.findall('[+-/*//()]|\d+',s))

Output
As you can see, it breaks down the string to an elemental level, not only reducing parenthesis:

['(', '1', '+', '2', ')', '+', '(', '3', '+', '4', ')']
user_138197140

I highly recommend @Cardstdani method, but here is a complex maze of if else statement which resembles your desired result.

def crush(string):
    crushed_string = []
    for i in range(0, len(string)):
        current_problem = ""
        if string[i] == "(":
            for x in range(i, len(string)):
                if string[x] == ")":
                    for y in range(i, x+1):
                        current_problem += string[y]
                    crushed_string.append(current_problem)
                    i = x+1
                    break

    return crushed_string

string = "(1+2)+(3+4)"
print(crush(string))

output:

['(1+2)', '(3+4)']
user_145411640
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