経線を描くのは，drawmeridians．
軸ラベル無しで，緯線だけ描くには
map.drawparallels(np.arange(-90.,91.,30.))
線無しで，軸ラベルだけを書くには
map.drawparallels(np.arange(-90.,91.,30.),labels=[1,0,0,0],fontsize=10,linewidth=0.0)
drawparallels は，緯線とそれに対応する軸ラベル（経度の数値）を描く．
Drawparallels draws lines across longitudes at specific latitudes and corresponding axis labels (numerical values of longitude).
You can draw only the axis labels, without lines by
map.drawparallels(np.arange(-90.,91.,30.),labels=[1,0,0,0],fontsize=10,linewidth=0.0)
You can draw only lines, without the axis labels by
Map.drawparallels (np.arange (-90., 91., 30.))
"drawmeridians" function draws the meridians.