Comparing strings - akin to Perl's "=~"

[Diez B. Roggisch]

krumblebunk at gmail.com wrote:

> Hello gurus,
> 
> I am learning Python to take the place of Perl in my toolbox of bits
> and bobs, and writing something pretty simple in theory, but having a
> hard time in Python with it - I am using a 3rd party module, and I am
> sure the etiquette of this channel states that this is pure Python
> questions only, but please bare with me in light of this, as my
> question does indeed relate to Python only.
> 
> I am grabbing the output from a SQL statement (using PyGreSQL 'pg'
> module), and when it returns the result, I am pulling it out as such:
> 
> try:
>     sc=pg.connect(dbname='mydb',host='dbhost',user='ppp')
> except pg.InternalError:
>     print "Failed to execute SQL: %s" % sql
>     exit
> 
> for foo in sc.query(sql).dictresult():   <- this returns a dict of the
> result
>     f=dict(foo)
>     for k in f.iteritems()
>         if k == '^Hostname':               <-- need this sort of
> behaviour - match a partial string.
>         print "%s" % f[3]              <-- ..and if true, need to pull
> out the 4th column on that line.
> 
> This breaks spectacularly -
> 
> any ideas?

Use the module "re" to create regular expressions & out of these
mather-objects that will give you what you need.

The idiom is roughly translated to this:

m = re.search(r"^Hostname')
if m:
   ...

Diez