useful python snippets

myutils.py

def alert(msg):
    '''return javascript alert window with givin message'''
    return '''<script type="text/javascript" charset="utf-8">
    alert("%s");
</script>''' % msg


from os.path import dirname as dirname
from os.path import join as pathjoin

def getPath(sufix=""):
    '''get absolute path of the current dir'''
    path = dirname(__file__)
    try:
        index=path.index("..")
        if index!=-1:
            path=path[:index]
    except:
        pass
    return pathjoin(path, sufix).replace('\\','/')

#force utf8
import sys
default_encoding = 'utf-8'
if sys.getdefaultencoding() != default_encoding:
    reload(sys)
    sys.setdefaultencoding(default_encoding)


from hashlib import md5
def md5ize(s):
    '''return the md5 encoding of a string'''
    return md5(s).hexdigest()


#integer file size to stringG
def format_size(size):
    if size<1024:
        return "%s Byte"% size
    elif size>=1024 and size <1024*1024:
        size /=1024
        return "%s Kb"% size
    elif size>=1024*1024 and size <1024*1024*1024:
        size /=(1024*1024)
        return "%s Mb"% size


#get parameter from url:
def get_V(p, regex=None):
    """return cgi GET parameter; strip white spaces at both ends if any;
    if verify pattern provided, do match test; only return matched values.
    Note: it uses re.match to check , not re.search.
    """
    import cgi
    form = cgi.FieldStorage()
    value= form.getfirst(p)

    if not value:
        return None
    value=value.strip()


    if regex is not None:
        import re
        if re.match(regex+"$",value):
            return value
        else:
            return None
    else:
         return value

def stringio():
    buffer = StringIO.StringIO()
    buffer.truncate(0)
    c.setopt(c.WRITEFUNCTION, buffer.write)
    value=buffer.getvalue()

def Do(cmdstr):
    from commands import getoutput
    try:
        return getoutput(cmdstr)
    except Exception, e:
        return str(e)

#sending email via local bash.
def Notify(content, receiver):
    from commands import getoutput as Do
    if not content:
        return

    subject="fanfou @ v2ex update"
    print content
    command="""mail -a "From: [email protected]" -s "%s" "%s" <<< "%s" """ % (subject, receiver, content)

    try:
        Do(command)
    except Exception, e:
        print str(e),"error!"



import urllib

def getHeader(url):
    '''get header information of a url'''
    remotefile=urllib.urlopen(url)
    return remotefile.headers.dict

def getRemoteFileLength(url, unit='k'):
    '''get length of an remote file, without downloading that file.'''
    remotefile=urllib.urlopen(url)
    unit=unit.upper()
    units={
        'B':1,
        'K':1024,
        'M':1024*1024,
        'G':1024*1024*1024,
    }

    try:
        length=remotefile.headers.dict['content-length']
    except:
        print 'no length infor. loading complete file to caclulate length'
        length=len(remotefile.read())

    reallen=float( float(length) / units[unit])

    formatedLength = "%.2f%s" % (reallen,unit)
    return formatedLength

#escaping html
html_escape_table = {
    "&": "&amp;",
    '"': "&quot;",
    "'": "&apos;",
    ">": "&gt;",
    "<": "&lt;",
    }

def html_escape(text):
    """Produce entities within text."""
    return "".join(html_escape_table.get(c,c) for c in text)