Substitution with Hash Values

Fri Apr 19 17:52:36 EDT 2002

> From: Jeff Jones [mailto:jeff at jonesj.com] 
> 
> I am a long time perl user who is trying to get a grip on 
> python.  I really like what I have seen so far, but I have 
> hit a little snag regarding substitution (like perl).
> 
> I use html templates for all of my CGI programming, and 
> everything that needs to be replaced is contained within 
> double curly braces ( {{value}} ).  In perl I use a hash to 
> keep all of the variables that are going to replace the 
> placeholders in the template, and replace them the following way:
> 
> 	....
> 	s/{{(.*?)}}/$hash{$1}/g;
> 	....
> 
> That substiution is accomplished as I read in the template file.
> 
> Can anyone tell me how I might do this in python?  I have 
> tried many different ways, but none seem to work.

# create a dictionary with your substitutions
subst = { 'value1' : 123, 'value2' : 'hello world' }

# create the text with appropriate %(dict-key)s placeholders
txt = """
  <body>
     this is %(value1)d and this is %(value2)s
  </body>
"""

# perform the substitutions
print txt % subst

Hth,
-- bjorn