How to show min and max values at the end of the axes - matplotlib

Question

I generate plots like below:
from pylab import *
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.ticker
import matplotlib.ticker as ticker
rcParams['axes.linewidth'] = 2 # set the value globally
rcParams['font.size'] = 16# set the value globally
rcParams['font.family'] = ['DejaVu Sans']
rcParams['mathtext.fontset'] = 'stix'
rcParams['legend.fontsize'] = 24
rcParams['axes.prop_cycle'] = cycler(color=['grey','b','g','r','orange'])
rc('lines', linewidth=2, linestyle='-',marker='o')
rcParams['axes.xmargin'] = 0
rcParams['axes.ymargin'] = 0
t = arange(0,21,1)
v = 2.0
s = v*t
plt.figure(figsize=(12, 4))
plt.plot(t,s,label='$s=%1.1f\cdot t$'%v)
plt.title('Wykres drogi w czasie $s=v\cdot t$')
plt.xlabel('Czas $t$, s')
plt.ylabel('Droga $s$, m')
plt.autoscale(enable=True, axis='both', tight=None)
legend(loc='best')
plt.xlim(min(t),max(t))
plt.ylim(min(s),max(s))
plt.grid()
plt.show()
When I am changing the value t = arange(0,21,1) for example to t = arange(0,20,1) which gives me for example on the x axis max value= 19.0 my max value dispirs from the x axis. The same situation is of course with y axis.
My question is how to force matplotlib to produce always plots where on the axes are max values just at the end of the axes like should be always for my purposes or should be possible to chose like an option?
Imiage from my program in Fortan I did some years ago
Matplotlib is more efficiens that I use it but there should be an opition like that (the picture above).
In this way I can always observe max min in text windows or do take addiional steps to make sure about max min values. I would like to read them from axes and the question is ...Are there such possibilites in mathplotlib ??? If not I will close the post.
Axes I am thinking about more or less

Answer 1

I see two ways to solve the problem.
Set the axes automatic limit mode to round numbers
In the rcParams you can do this with
rcParams['axes.autolimit_mode'] = 'round_numbers'
And turn off the manual axes limits with min and max
plt.xlim(min(t),max(t))
plt.ylim(min(s),max(s))
This will produce the image below. Still, the extreme values of the axes are shown at the nearest "round numbers", but the user can approximately catch the data range limits. If you need the exact value to be displayed, you can see the second solution which cannot be directly used from the rcParams.
or – Manually generate axes ticks
This solution implies explicitly asking for a given number of ticks. I guess there is a way to automatize it depending on the axes size etc. But if you are dealing with more or less every time the same graph size, you can decide a fixed number of ticks manually. This can be done with
plt.xlim(min(t),max(t))
plt.ylim(min(s),max(s))
plt.xticks(np.linspace(t.min(), t.max(), 7)) # arbitrary chosen
plt.yticks(np.linspace(s.min(), s.max(), 5)) # arbitrary chosen
generated the image below, quite similar to your image example.