Bring radial axes labels in front of lines of polar plot matplotlib

Question

I am trying to get the radial (or y-axis) labels on a polar plot to go on top of the lines that are plotted on the graph. Right now they are underneath the lines and are covered up.

Here is a simplified version of the code for just one city and one line:

fig, ax = plt.subplots(figsize=(10,6) , nrows=1, ncols=1,subplot_kw=dict(projection='polar'))
rmax = 15
rticks = np.arange(9,rmax,1.5)
rticklabel = np.arange(18,rmax*2,3).astype(int)

theta = np.arange(0,6.3, 0.17) #plots a circle
r = np.ones(len(theta))*(21/2)
ax.plot(theta, r,c='r', linestyle='-',linewidth = 4,zorder=1)

ax.set_rmax(rmax)
ax.set_rticks(rticks)  # less radial ticks

ax.set_xticklabels([])  
ax.set_rlabel_position(285)  # get radial labels away from plotted line
ax.grid(True)

ax.set_facecolor('white') 
ax.yaxis.grid(color='silver', linestyle=':',linewidth = 1.5,zorder=10)
ax.set_yticklabels(rticklabel,fontsize=12,zorder=10) #this zorder does nothing

I have already tried this:

plt.rcParams["axes.axisbelow"] = False

This brings the text to the front as I wish, however, it also brings the grid lines. I would like those to stay behind the colored lines.

I have also tried changing the zorder of the yaxis grid, but that does not work.

Most solutions for this are not for the polar axis. Any suggestions?

Answer 1

Unfortunately it seems that the zorder of the grid and labes is tied to that of the axes: https://matplotlib.org/api/_as_gen/matplotlib.axes.Axes.grid.html

One possible solution even if not elegant is to draw the gridlines yourself

fig, ax = plt.subplots(figsize=(10,6) , nrows=1, ncols=1,subplot_kw=dict(projection='polar'))
rmax = 15
rticks = np.arange(9,rmax,1.5)
rticklabel = np.arange(18,rmax*2,3).astype(int)

theta = np.arange(0,6.3, 0.17) #plots a circle
r = np.ones(len(theta))*(21/2)
ax.plot(theta, r,c='r', linestyle='-',linewidth = 4,zorder=2)

ax.set_rticks(rticks)  # less radial ticks

ax.set_xticklabels([])  
ax.set_rlabel_position(285)  # get radial labels away from plotted line
ax.xaxis.grid(True)
ax.yaxis.grid(False)

ax.set_facecolor('white') 
ax.set_yticklabels(rticklabel,fontsize=12,zorder=10) #this zorder does nothing
ax.yaxis.set_zorder(10)
#ax.yaxis.grid(color='silver', linestyle=':',linewidth = 1.5,zorder=10)

x = np.arange(0,2*np.pi,0.05)
y = np.outer( np.ones(x.shape), rticks)
ax.plot( x,y, zorder=1, color='silver', linestyle=':')
ax.set_ylim(0,rmax)