Archive
Roman numbers to decimal
Problem
You want to convert Roman numbers to decimal and decimal numbers to Roman numbers.
Solution
I found a module for this task called romanclass (http://pypi.python.org/pypi/romanclass).
I wrote a simple wrapper around it, available here.
Check iO: A game where you code in Python
Check iO is a browser-based game where you need to solve problems in Python in order to advance.
Update (20121109)
Guido found it too :)
Determine the name of the current function
Problem
You want to determine the name of the current function.
Solution
import sys
def whoami():
print '# this function is:', sys._getframe().f_code.co_name
print '# this line number is:', sys._getframe().f_lineno
print '# this file\'s name is:', sys._getframe().f_code.co_filename
whoami()
Output:
# this function is: whoami # this line number is: 5 # this file's name is: na.py
Also, by calling sys._getframe(1), you can get this information for the *caller* of the current function. So you can package this functionality up into your own handy functions:
import sys
def get_function_name():
return sys._getframe(1).f_code.co_name
def whoami():
func_name = get_function_name()
print '# current function\'s name:', func_name
whoami()
Output:
# current function's name: whoami
This tip is from here.
Building Skills in Python
I found a freely available Python book at Linuxtopia called “Building Skills in Python“.
This Linuxtopia site is great! Check it out!
How to Write a Spelling Corrector
You can also check out his site.
BeautifulSoup: _detectEncoding error
Problem
While parsing an HTML page with BeautifulSoup, I got a similar error message:
File ".../BeautifulSoup.py", line 1915, in _detectEncoding
'^<\?.*encoding=[\'"](.*?)[\'"].*\?>').match(xml_data)
TypeError: expected string or buffer
In the code I had this:
text = get_page(url) soup = BeautifulSoup(text)
Solution
text = get_page(url) text = str(text) # here is the trick soup = BeautifulSoup(text)
Tip from here.
Check Gmail for new messages
Problem
I want to check my new Gmail messages periodically. When I get a message from a specific sender (with a specific Subject), I want to trigger some action. How to do that?
Solution
Fortunately, there is an atom feed of unread Gmail messages at https://mail.google.com/mail/feed/atom. All you have to do it is visit this page, send your login credentials, fetch the feed and process it.
import urllib2
FEED_URL = 'https://mail.google.com/mail/feed/atom'
def get_unread_msgs(user, passwd):
auth_handler = urllib2.HTTPBasicAuthHandler()
auth_handler.add_password(
realm='New mail feed',
uri='https://mail.google.com',
user='{user}@gmail.com'.format(user=user),
passwd=passwd
)
opener = urllib2.build_opener(auth_handler)
urllib2.install_opener(opener)
feed = urllib2.urlopen(FEED_URL)
return feed.read()
##########
if __name__ == "__main__":
import getpass
user = raw_input('Username: ')
passwd = getpass.getpass('Password: ')
print get_unread_msgs(user, passwd)
For reading XML I use the untangle module:
import untangle # sudo pip install untangle
xml = get_unread_msgs(USER, PASSWORD)
o = untangle.parse(xml)
try:
for e in o.feed.entry:
title = e.title.cdata
print title
except IndexError:
pass # no new mail
Links
- How to auto log into gmail atom feed with Python? (I took the script from here)
- Read XML painlessly (the untangle module)
The best free Python resources
Print unicode text to the terminal
Problem
I wrote a script in Eclipse-PyDev that prints some text with accented characters to the standard output. It runs fine in the IDE but it breaks in the console:
UnicodeEncodeError: 'ascii' codec can't encode character u'\xf3' in position 11: ordinal not in range(128)
This thing bugged me for a long time but now I found a working solution.
Solution
Insert the following in your source code:
import sys
reload(sys)
sys.setdefaultencoding("utf-8")
I found this trick here. “This allows you to switch from the default ASCII to other encodings such as UTF-8, which the Python runtime will use whenever it has to decode a string buffer to unicode.”
Related
Python Adventures 
You must be logged in to post a comment.