print("Using fake urllib module.") import random class Request: def __init__(self, url): self.url = url def __enter__(self): return self def __exit__(self, type, value, tb): pass def read(self): val = random.randint(0, 5) if val == 0: return "ERROR".encode() elif val < 4: return "OK".encode() raise Exception("Test Network Exception") def urlopen(url): print("> URLLIB: opening url %s" % url) return Request(url)