Python String Templates

Question

We are using string template to replace some values in Python String by supplying a dict . It works fine . However despite using safe_substitute this below code doesnt work as expected . Any idea why ?

from string import Template 
obj = Template("$$Tag$$") 
obj.safe_substitute({}) 

Output : '$Tag$' Expected : '$$Tag$$' 
(As there is no value to replace in the dict supplied .)

This same issue happens for '####' if I make '##' as the delimiter . Anyone knows why is it ignoring an extra delimiter ? Just trying to understand what happens under the hood .

doesnt work as expected: What would you have expected exactly? — njzk2
– njzk2, Commented Nov 20, 2013 at 19:06
Any reason for the down vote expect I didnt clarify the expected result ? Hope its a SO question . — Nishant
– Nishant, Commented Nov 20, 2013 at 19:08
Awesome guys ! I get the point , escaping thats the only way to put the real value if that is a delimiter ! Thats the detail I wanted to know . Its same as '\\' in Linux bash I think . Anyway thanks . — Nishant
– Nishant, Commented Nov 20, 2013 at 19:10

Ashwini Chaudhary · Accepted Answer · 2013-11-20 19:10:50Z

2

From docs:

$$ is an escape; it is replaced with a single $.

If you want double $, then you can use something like:

>>> obj = Template("$$$$Tag$$$$")
>>> obj.safe_substitute({})
'$$Tag$$'
>>> obj.safe_substitute({'Tag':1})
'$$Tag$$'
>>> obj = Template("$$$Tag$$$") #First $ escapes the second $
>>> obj.safe_substitute({'Tag':1})
'$1$$'

edited Nov 20, 2013 at 19:10

answered Nov 20, 2013 at 19:05

Ashwini Chaudhary

252k60 gold badges478 silver badges519 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

njzk2 · Accepted Answer · 2013-11-20 19:05:20Z

1

From the doc :

"$$" is an escape; it is replaced with a single "$".

answered Nov 20, 2013 at 19:05

njzk2

39.4k7 gold badges72 silver badges111 bronze badges

Comments

Roberto Bonvallet · Accepted Answer · 2013-11-20 19:07:59Z

1

You have to put two dollar signs for each one that you want in the output:

>>> Template('$$$$Tag$$$$').substitute()
'$$Tag$$'

answered Nov 20, 2013 at 19:07

Roberto Bonvallet

33.7k5 gold badges45 silver badges57 bronze badges

Collectives™ on Stack Overflow

Python String Templates

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related