Question

I have a question, which is basically a question on Python template engine capability.

Suppose I have the following code:

import string as st

def foo(bar):
    if bar:
        t = 'world'
    else:
        t = 'not happening'

    return t

temp = st.Template("hello $bar")
final = temp.some_substitute_magic()

and then

print final

should give

hello world

Is it possible to do that with some Python magic?

I know how to do a safe_substitute with a dictionary, but I would like to know how to do a substitute with a function to which every identifier (in this case $bar) is passed and then the returned value is substituted into the template.

Answer 1

Quite easy actually 🙂

Just emulate the workings of a dict and you’re done.

class Scope(object):
    def __getitem__(self, key):
        return 'call for %s' % key

print final.substitute(Scope())