String interpolation from collection type

Question

I have a string interpolation issue which I am not sure how to get it straight. Much appreciate any help towards solving this.

Abstract: I have a string template that composes an email body. This string template has both static and dynamic contents. The aim is to fill all dynamic parts of the template with context-specific values that will be supplied with the help of a dictionary.

Question: If you look at the code and output, I am able to extract the Key/Value from the dictionary (first and second print output). However, when the Values become collection type such as list or tuple, I have trouble in extracting them; especially the dynamic part of the text is getting embedded with the [ ] or ( )(third print output).

Is it possible to avoid [ ] or ( ) constructs from the output ? I would prefer the output as

'foo', 'bar'

instead of

['foo', 'bar']

import string

values = {'dynamic': 'foo'}

t = string.Template("""
Static contents        : $dynamic
More static contents.
""")

print('Body:', t.substitute(values))

values = {'dynamic': 'foo, bar'}

print('Body:', t.substitute(values))

values = {'dynamic': ['foo', 'bar']}

print('Body:', t.substitute(values))

Note: Given logic and example only represent the idea of how I am injecting one dynamic content. In reality, I have more than one dynamic variables to be filled. Something like what Mail Merge does in Microsoft Word. E.g:

values = {'surname': 'xxx',
'email':'[email protected]',
'title':'Mr',
'reference':'xxxxx'
'contacts':['a','b','c']
}

Answer 1

I don't have complete grasp over what exactly you want but instead of using templates why not use regular strings with string formatting?

For Example:

t = """
Static contents : {dynamic}
More static contents.
"""

values = {
  'str': 'foo, bar',
  'dict': {'test': 'foo'},
  'list': ['foo', 'bar'],
  'list2': ["'foo'", "'bar'"],
}

print('Body:', t.format(dynamic=values['str']))
print('Body:', t.format(dynamic=', '.join(values['dict'].values())))

print('Body:', t.format(dynamic=str(values['list'])[1:-1]))
# OR (the less exception prone way)
print('Body:', t.format(dynamic=', '.join(values['list2'])))

Output:

Body:
Static contents : foo, bar
More static contents.

Body:
Static contents : foo, bar2
More static contents.

Body:
Static contents : 'foo', 'bar'
More static contents.

Body:
Static contents : 'foo', 'bar'
More static contents.