Inconsistent tick behavior between themes

[jbechtel]

When switching between different themes, the minor ticks are inconsistently displayed. For instance, for theme_grey() and theme_538() the minor ticks are not displayed, but for theme_bw() and theme_xkcd() they are displayed. It would be great if the minor ticks were displayed consistently between all themes (I prefer not showing them!). But in the meantime, if I would like to use the theme_bw() with no minor ticks (but keeping the minor grid lines), how would I go about that?

Here are some examples:

from plotnine import *
from plotnine.data import mtcars

(ggplot(mtcars, aes('wt', 'mpg', color='factor(gear)'))
 + geom_point()
 + stat_smooth(method='lm')
 + facet_wrap('~gear')
 + theme_grey()
)

(ggplot(mtcars, aes('wt', 'mpg', color='factor(gear)'))
 + geom_point()
 + stat_smooth(method='lm')
 + facet_wrap('~gear')
 + theme_bw()
)

(ggplot(mtcars, aes('wt', 'mpg', color='factor(gear)'))
 + geom_point()
 + stat_smooth(method='lm')
 + facet_wrap('~gear')
 + theme_538()
)

(ggplot(mtcars, aes('wt', 'mpg', color='factor(gear)'))
 + geom_point()
 + stat_smooth(method='lm')
 + facet_wrap('~gear')
 + theme_xkcd())

[has2k1]

But in the meantime, if I would like to use the theme_bw() with no minor ticks (but keeping the minor grid lines), how would I go about that?

+ theme(
    axis_ticks_minor=element_blank(),
    panel_grid_minor=element_line(color='red')
)