from string import Template

data = dict(item = "candy", price = 8, qty = 2)

# define the template
t = Template("Simon bought $qty $item for $price dollar")   
print(t.substitute(data))

Output:

Simon bought 2 candy for 8 dollar

Templates support $-based substitutions instead of %-based substitution. Substitute (mapping, keywords) performs template substitution, returning a new string.

Mapping is any dictionary-like object with keys that match with the template placeholders. In this example, price and qty are placeholders. Keyword arguments can also be used as placeholders. Placeholders from keywords take precedence if both are present.