use of In[] tag in pandas

[paragmedsinge]

I was going through this code related to linear regression and was trying same in IDLE but idle is not recognizing Out[X,Y] or In[X] . Pandas moudle is already installed and imported in my .py file.
code is something like this

Out[142]:(24,24)

In[143]:plt.scatter(xs,ys) 

its gives me error

NameError: name 'In' is not defined

sameerror comes for 'Out' too.

Any help appreciated.