Dirtiest Brainfuck Interpreter I've Ever Seen (But It Works)

dirty-brainfuck-interpreter.py

memory = [0]
pointer = 0
loop = False
loop_start = 0
loop_point = 0

bf_code = '<BRAINFUCK CODE>'

def check_char(char):
    global memory, pointer
    match char:
        case '+':
            memory[pointer] += 1
        case '-':
            memory[pointer] -= 1
        case '>':
            pointer += 1
            if len(memory) < pointer+1:
                memory.append(0)
        case '<':
            if pointer > 0:
                pointer -= 1
        case '.':
            print(chr(memory[pointer]), end='')

for char_index in range(len(bf_code)):
    char = bf_code[char_index]
    if char in '+-><.':
        check_char(char)
    elif char == '[':
        loop = True
        loop_start = char_index+1
        loop_point = pointer
    elif char == ']':
        loop_end = char_index
        while loop:
            for loop_char in bf_code[loop_start:loop_end]:
                check_char(loop_char)
                if not memory[loop_point]:
                    loop = False
    else:
        pass