In _pyplot.plot_, the parameter _fmt_ defines basic formatting like color, marker and linestyle. In _pyplot.plot_date_, the parameter _fmt_ defines the plot format string. This is inconsistency may lead to errors.
In pyplot.plot, the parameter fmt defines basic formatting like color, marker and linestyle.
In pyplot.plot_date, the parameter fmt defines the plot format string.
This is inconsistency may lead to errors.