color version - PET: Python Entre Todos - Python Argentina

Using additional libraries and virtualenv
Author: Tomas Zulberti
>>> msg = MIMEText(" This is the e-mail's content... ")
>>> msg['From'] = USERNAME
>>> msg['To'] = USERNAME
>>> msg['Subject'] = "This is the e-mail's subject"
>>> mailServer.sendmail("tzulberti@gmail.com", "tzulberti@gmail.com", msg.as_string())
Lets read a web page’s content.
The subjects I’m going to talk about are:
• Python’s standard library
• What to do when something isn’t on that library.
• Installing additional libraries
• Using virtualenv to solve the problems that show up
Python comes with around 350 usable libraries. http://docs.python.org/library/index.html
There’s a bit of everything:
• Stuff to work with mails
• Fetching web pages
• Interacting with the operating system
• Working with compressed files
• Parsing different types of documents (xml, json, etc…)
AND MANY MANY MORE….
But first of all, lets see some examples of things you can do with Python’s built-in
batteries.
Lets send an e-mail using a GMail account:
>>> import smtplib
>>> from email.MIMEText import MIMEText
>>> USERNAME = "tzulberti@gmail.com" # Put your username here
>>> PASSWORD = "not-gonna-tell" # Put your password here
>>> mailServer = smtplib.SMTP('smtp.gmail.com',587)
>>> mailServer.ehlo()
>>> mailServer.starttls()
>>> mailServer.ehlo()
>>> mailServer.login(USERNAME, PASSWORD)
>>> from urllib2 import urlopen
>>> response = urlopen("http://python.org.ar/pyar/")
>>> html_content = response.read()
>>> print html_content
Inicio - PyAr - Python Argentina
Or work with compressed files
>>> import zipfile
>>> compressed_file = zipfile.ZipFile("THA_FILE.zip", "r")
>>> for name in compressed_file.namelist():
... print name
>>> compressed_file.extract()
But python’s standard library doesn’t have it all:
• It doesn’t know how to read some file formats (yaml, mp3, video)
• Web Frameworks (pylons, django, web2py)
• Using APIs from Youtube, Deliciosus, etc….
We’ve seen that the standard library can do many things, but there are some that are
easier if done with third-party libraries:
• Web frameworks save us from some repetitive work.
• API bindings save us the work of reading a lot of documentation on the services
they wrap.