Function divide_json

example_code/item_080.py:130–157

(path)

DIE_IN_ELSE_BLOCK = False

def divide_json(path):
    print("* Opening file")
    handle = open(path, "r+")                        # May raise OSError
    try:
        print("* Reading data")
        data = handle.read()                         # May raise UnicodeDecodeError
        print("* Loading JSON data")
        op = json.loads(data)                        # May raise ValueError
        print("* Performing calculation")
        value = op["numerator"] / op["denominator"]  # May raise ZeroDivisionError
    except ZeroDivisionError:
        print("* Handling ZeroDivisionError")
        return UNDEFINED
    else:
        print("* Writing calculation")
        op["result"] = value
        result = json.dumps(op)
        handle.seek(0)                               # May raise OSError
        if DIE_IN_ELSE_BLOCK:
            import errno
            import os

            raise OSError(errno.ENOSPC, os.strerror(errno.ENOSPC))
        handle.write(result)                         # May raise OSError
        return value
    finally:
        print("* Calling close()")
        handle.close()                               # Always runs


print("Example 9")