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PyPlot - Additional padding for xticklabels if keywords are not enough

I have a plot where I set my ticks and labels manually, because pyplot did not do the job to my full satisfaction. I align the labels using the following code:
for tick in self.axes.xaxis.get_minorticklabels():
tick.set_horizontalalignment('right')
tick.set_rotation(40)
This is basically fine, but I'd like the labels to move a little bit further to the left (center is too far). I only found padding for the axis label in this post, but not for the tick labels. Is there something similar like labelpad=X to move the tick labels in horizontal direction?

You can use the Axes.set_tick_params() function to adjust the padding between the axe and the tick labels (minor, major, or both)
ax.xaxis.set_tick_params(which='minor', pad=25)

customize ticks label when sharex is on in matplotlib

I have two stacked subplots which share the x axis, for both subplots visibility of ticks is set to false because I don't want to see tick labels. after having plotted both subplots, I would like to put some extra ticks on x-asis, only for second subplot, but they don't have to became the main ticks.
I mean, doing this:
#xticks = list of x points
#xlabs = list of labels
#secondplot.set_xticks(xticks)
#secondplot.set_xticklabels(xlabs)
will change the first sublplot grid according to these new ticks as if they became the new major ticks. is there a way to label just some x-axis point in second subplot without affecting the whole plots area? thank you

I know im late to the party but I faced a similar problem and want to share my solution, in case anyone else needs help.
You can use matplotlib.axes.Axes.tick_params to control the style of both major and minor ticks of the axes. Setting the tick lengths of the first subplot to 0 should do the trick:
ax.tick_params(axis="x", which="both", length=0.)
axis ("x", "y" or "both") selects the axes, on which the setting has an effect, which ("major", "minor" or "both") chooses the tick type.
Of course you can then also set major and minor ticks with ax.set_xticks(ticks, minor=False). A full example:
import matplotlib.pyplot as plt
fig, axarr = plt.subplots(2, 1, sharex="col")
axarr[0].plot(range(11))
axarr[1].plot(range(11)[::-1])
axarr[0].tick_params(axis="x", which="both", length=0.)
axarr[1].set_xticks(range(0, 11, 3))
axarr[1].set_xticks(range(0, 11), minor=True)
plt.show()
which yields: https://i.stack.imgur.com/oc7y0.png

This works for removing the tick labels from a single axis when using sharex, but I don't see a solution to also remove the ticks..
import matplotlib.pylab as pl
pl.figure()
ax1=pl.subplot(211)
ax1.plot([0,10],[0,10])
ax2=pl.subplot(212, sharex=ax1)
ax2.plot([0,10],[10,0])
pl.setp(ax1.get_xticklabels(), visible=False)

How to print Y axis label horizontally in a matplotlib / pylab chart?

I'm creating very simple charts with matplotlib / pylab Python module. The letter "y" that labels the Y axis is on its side. You would expect this if the label was longer, such as a word, so as not to extend the outside of the graph to the left too much. But for a one letter label, this doesn't make sense, the label should be upright. My searches have come up blank. How can I print the "y" horizontally?

It is very simple. After plotting the label, you can simply change the rotation:
import matplotlib.pyplot as plt
plt.ion()
plt.plot([1, 2, 3])
plt.ylabel("y", rotation=0)
# or
# h = plt.ylabel("y")
# h.set_rotation(0)
plt.draw()

Expanding on the accepted answer, when we work with a particular axes object ax:
ax.set_ylabel('abc', rotation=0, fontsize=20, labelpad=20)
Note that often the labelpad will need to be adjusted manually too — otherwise the "abc" will intrude onto the plot.
From brief experiments I'm guessing that labelpad is the offset between the bounding box of the tick labels and the y-label's centre. (So, not quite the padding the name implies — it would have been more intuitive if this was the gap to the label's bounding box instead.)

How to give Matplolib imshow plot colorbars a label

We can give x and y axes labels for the main axes. Is there any way to similarly give a color bar a label? Alternately, is there any way to append a unit to one or more colorbar ticks?

Like many axis objects, colorbar() has a set_label() method:
cbar = fig.colorbar(heatmap)
cbar.set_label('Label name',size=18)

You use annotate to place text just about anywhere and add an arrow to what it refers to see some examples here.

autofmt_xdate deletes x-axis labels of all subplots

I use autofmt_xdate to plot long x-axis labels in a readable way. The problem is, when I want to combine different subplots, the x-axis labeling of the other subplots disappears, which I do not appreciate for the leftmost subplot in the figure below (two rows high). Is there a way to prevent autofmt_xdate from quenching the other x-axis labels? Or is there another way to rotate the labels? As you can see I experimented with xticks and "rotate" as well, but the results were not satisfying because the labels were rotated around their center, which resulted in messy labeling.
Script that produces plot below:
from matplotlib import pyplot as plt
from numpy import arange
import numpy
from matplotlib import rc
rc("figure",figsize=(15,10))
#rc('figure.subplot',bottom=0.1,hspace=0.1)
rc("legend",fontsize=16)
fig = plt.figure()
Test_Data = numpy.random.normal(size=20)
fig = plt.figure()
Dimension = (2,3)
plt.subplot2grid(Dimension, (0,0),rowspan=2)
plt.plot(Test_Data)
plt.subplot2grid(Dimension, (0,1),colspan=2)
for i,j in zip(Test_Data,arange(len(Test_Data))):
plt.bar(i,j)
plt.legend(arange(len(Test_Data)))
plt.subplot2grid(Dimension, (1,1),colspan=2)
xticks = [r"%s (%i)" % (a,b) for a,b in zip(Test_Data,Test_Data)]
plt.xticks(arange(len(Test_Data)),xticks)
fig.autofmt_xdate()
plt.ylabel(r'$Some Latex Formula/Divided by some Latex Formula$',fontsize=14)
plt.plot(Test_Data)
#plt.setp(plt.xticks()[1],rotation=30)
plt.tight_layout()
#plt.show()

This is actually a feature of the autofmt_xdate method. From the documentation of the autofmt_xdate method:
Date ticklabels often overlap, so it is useful to rotate them and right align them. Also, a common use case is a number of subplots with shared xaxes where the x-axis is date data. The ticklabels are often long, and it helps to rotate them on the bottom subplot and turn them off on other subplots, as well as turn off xlabels.
If you want to rotate the xticklabels of the bottom right subplot only, use
plt.setp(plt.xticks()[1], rotation=30, ha='right') # ha is the same as horizontalalignment
This rotates the ticklabels 30 degrees and right aligns them (same result as when using autofmt_xdate) for the bottom right subplot, leaving the two other subplots unchanged.