__init__.py

from ._convert import _convert

def convert(chart):
    """Convert an altair encoding to a Matplotlib figure
    
    Parameters
    ----------
    chart
        The Altair chart object generated by Altair

    Returns
    -------
    fig
        The Matplotlib figure
    ax
        The Matplotlib axes object
    """
    
    fig, ax = plt.subplots()
    
    if chart.mark is ('point', 'circle', 'square'):  # scatter
        mapping = _convert(chart)
        ax.scatter(**mapping)
    elif chart.mark == 'line':  # line
        data = _data.get_df()
        if 'color' or 'stroke' in data:
            for _, subset in data.groupby(color):
                mapping = _convert(chart, subset)
                ax.plot(**mapping)

    return fig, ax