AoC 2017: Day 9 (Parts 1 & 2)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# Advent of Code 2017 -- Day 9: Stream Processing -- Alex Ray
# https://adventofcode.com/2017/day/9

def recording(stream):

    global total_score
    global group_depth
    global collecting_garbage

    print("Recording...")

    while True:
        current = stream.pop(0)
        print(current)
        if current == "!":
            x = stream.pop(0)
            print("cancelled: %s" % x)
            # stream.pop(0)
            continue
        elif current == "<":
            collecting_garbage = True
            return
        elif current == "{":
            group_depth += 1
            continue
        elif current == "}":
            total_score += group_depth
            group_depth -= 1
            continue
        else:
            pass

def trashing(stream):

    global collecting_garbage
    global piecesOfTrash

    print("Collecting garbage...")

    while True:
        char = stream.pop(0)
        print(char)
        if char == "!":
            x = stream.pop(0)
            print("cancelled: %s" % x)
            # stream.pop(0)
            continue
        elif char == ">":
            collecting_garbage = False
            return
        else:
            piecesOfTrash += 1  # <--- PART TWO


total_score = 0
group_depth = 0
collecting_garbage = False
piecesOfTrash = 0

def parsing(string):
    while string:
        while not collecting_garbage:
            recording(string)
        trashing(string)

with open('day9input.txt', 'r') as f:
    string = list(f.read())

try:
    parsing(string)
except IndexError:
    print("Reached end of input.")

print("Total score: %r" % total_score)
print("Trash collected: %r " % piecesOfTrash)