To check if a set is a subset of another set in python, a solution is to use the python function issubset:
Lets create a first set called s:
s = {1,2,3,4,5,6,7,8,9}
to check if another subset called s1 defined as
s1 = {1}
is a subset of set s just called issubset():
print( s1.issubset(s) )
returns here
True
Another example with a set of 2 elements:
s1 = {4,6}
print( s1.issubset(s) )
gives
True
or 4 elements:
s1 = {4,6,7,1}
print( s1.issubset(s) )
gives
True
but
s1 = {7,12}
print( s1.issubset(s) )
returns
False