Flipping Data between Files on a Micro:Bit

flip.py

import os
from microbit import *

def init_state():
    # Hopefully, this creates zero-length files
    # in the filesystem
    A_size = 0
    B_size = 0
    try:
        A_size = os.size("A.txt")
    except:
        pass
        
    # display.scroll("A" + str(A_size), wait = False)
    
    if A_size == 0:
        with open("A.txt", "w") as A:
            A.write("")
    try:
        B_size = os.size("B.txt")
    except:
        pass
    if B_size == 0:
        with open("B.txt", "w") as B:
            B.write("")

def extend_data(data):
    A_size = os.size("A.txt")
    B_size = os.size("B.txt")
    # If A is bigger, we copy from A to B, and
    # then proceed to extend B.
    if A_size > B_size:
        with open("B.txt", "w") as B:
            try:
                with open("A.txt", "r") as A:
                    line = A.readline()
                    while len(line) > 1:
                        B.write(line)
                        line = A.readline()
            except: 
                pass
            B.write(data)
            B.write("\n")
    # Otherwise, B is bigger, and we will
    # overwrite A, copying B + the extension.
    else:
        with open("A.txt", "w") as A:
            try:
                with open("B.txt", "r") as B:
                    line = B.readline()
                    while len(line) > 1:
                        A.write(line)
                        line = B.readline()
            except:
                pass
            A.write(data)
            A.write("\n")

# Setup
init_state()
# Loop
counter = 0
while True:
    sleep(1000)
    extend_data(str(counter) + "," + str(temperature()))
    counter = counter + 1