def _regressLiteralType(x):
    """The function returns the literal with its proper type, such as int,
    float, or string from the input string x

    Examples
    --------
    >>> _regressLiteralType("1")->1
    >>> _regressLiteralType("1.0")->1.0
    >>> _regressLiteralType("1e-3")->0.001
    >>> _regressLiteralType("YUV")->'YUV'
    >>> _regressLiteralType("YO8")->'YO8'
    """
    try:
        float(x)  # Test for numeric or string
        lit = float(x) if set(['.','e','E']).intersection(x) else int(x)
    except ValueError:
        lit = str(x)
    return lit