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

```python
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: 

```python
print(len(my_seq))
```

You can access elements of a Seq object: 

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

You can also slice a Seq object:

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

You can add Seq objects together: 

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

You can change the case of Seq objects: 

```python
print(my_seq2.lower())
```

When run in Python, the output will be: 

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

How Sequences Act like Strings 

-      Complements and Reverse Complements 
-      Transcription
-      Translation 
-      Translation Table 
-      Mutable Seq Objects 

How Sequences Differ from Strings 

In BioPython, sequences act similarly to normal string objects in Python as they are essentially a bunch of letters. While there a lot of methods that support both the Seq and string object, the Seq object differs from string objects in the methods that can be used on it. 

Boston University

- Sequences
- Sequence Annotation Objects 
- Multiple Sequence Annotation Objects 
- BLAST

Basics 

This link leads to a page describing a large overview of BioPython and what it can do : 
http://biopython.org/DIST/docs/tutorial/Tutorial.html

Learn Before

Related

Learn After