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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def confirm_input(user_input):
 """Check user input for yes, no, or an exit signal."""

    if isinstance(user_input, list):
        user_input = ''.join(user_input)

    try:
        u_inp = user_input.lower().strip()
    except AttributeError:
        u_inp = user_input

    # Check for exit signal
    if u_inp in ('q', 'quit', 'exit'):
        sys.exit()
    if u_inp in ('y', 'yes'):
        return True
    return False