A few examples.... You can iterate over the elements in the Seq object the same as a string object :

from Bio.Seq import Seq
my_seq = Seq("ATGCA")
for index, letter in enumerate(my_seq):
    print((index, letter)) 

You can find the length of the Seq object:

print(len(my_seq))

You can access elements of a Seq object:

print(my_seq[2])
print(my_seq[-1])

You can also slice a Seq object:

print(my_seq[4:0:-2])

You can add Seq objects together:

my_seq2 = Seq("GTCATC")
print(my_seq + my_seq2)

You can change the case of Seq objects:

print(my_seq2.lower())

When run in Python, the output will be:

(0, 'A')
(1, 'T')
(2, 'G')
(3, 'C')
(4, 'A')
5
G
A
AG
ATGCAGTCATC
gtcatc