Normalizes glyph left margin.

    * **value** must be a :ref:`type-int-float` or `None`.
    * Returned value is the same type as the input value.

def normalizeGlyphLeftMargin(value):
    """
    Normalizes glyph left margin.

    * **value** must be a :ref:`type-int-float` or `None`.
    * Returned value is the same type as the input value.
    """
    if not isinstance(value, (int, float)) and value is not None:
        raise TypeError("Glyph left margin must be an :ref:`type-int-float`, "
                        "not %s." % type(value).__name__)
    return value