How to reuse and plot more than once the same plot

Question

Using matplotlib, on Jupyter books, I want to make a figure with some plots, show it, add more plots, and show it again (old and new plots)

instead, it shows me only new plots on the new second image

This is the code I have:

import numpy as np
%matplotlib inline  
import matplotlib.pyplot as plt

a=np.random.rand(10,)
b=np.random.rand(10,)

fig1 = plt.figure(1)
plt.plot(a,'b')
#plt.draw();
plt.show();

plt.figure(1)
plt.plot(b,'g--')
plt.show();

left is what I have, right is what I want :

enter image description here

---

The question upside has been reduced to the most simplistic form, therefore I may have not explain that I do not want to having to recreate the figure each time (as it has about 15 lines to configure as I desire)

This is an example of code I DO NOT want:

import numpy as np
%matplotlib inline  
import matplotlib.pyplot as plt

a=np.random.rand(10,)
b=np.random.rand(10,)
c=np.random.rand(10,)

plt.plot(a, 'b')
plt.grid(True)

dig, ax = plt.subplots(1)
ax.plot(a,'b')
ax.plot(b,'g--')

dig, bx = plt.subplots(1)
bx.plot(a,'b')
bx.plot(b,'g--')
bx.plot(c,'r.')

plt.show()

this is a sort of pseudocode I would expect:

a=np.random.rand(10,)
b=np.random.rand(10,)
c=np.random.rand(10,)

my_plot = plt.figure()
my_plot.grid(True)

my_plot.addplot(a,'b')
my_plot.show()

my_plot.addplot(a,'g--')
my_plot.show()

my_plot.addplot(a,'r.')
my_plot.show()

(I know, this is not phyton/matplotlib, but I am sure something elegant like this should be possible)

Answer 1

import numpy as np
%matplotlib inline  
import matplotlib.pyplot as plt

a=np.random.rand(10,)
b=np.random.rand(10,)
c=np.random.rand(10,)
d=np.random.rand(10,)

p = [a,b,c,d]
colors = ['r','g','b', 'g--']
for i in range(len(p)):
    fig, ax = plt.subplots(1)
    for j in range(i + 1):
        ax.plot(p[j], colors[j])