How to insert variable string into multiline comment in Python?

Question

I want do define a Python function with exec like this:

exec """def my_func(alpha = 'a'):
  return alpha"""

It works. However, for a specific reason I want to to define the alpha = 'a' in a separate string:

s = "alpha = 'a'"
exec """def my_func(s):
  return alpha"""

but this one doesn't work. Is there a way to insert a string variable content into multiline comment string this way?

Why are you doing this with exec? What is your actual use case? — Chris_Rands
– Chris_Rands, Commented Nov 13, 2017 at 8:56
Possible duplicate of How do I put a variable inside a String in Python? — Chris_Rands
– Chris_Rands, Commented Nov 13, 2017 at 8:57
This is not a "multiline comment", it's a triple quoted (multiline) string literal. The fact that triple quoted strings are often used as docstrings does not make them comments. And since it's a string literal, all the usual string formatting operations (which are extensively documented) are available. — bruno desthuilliers
– bruno desthuilliers, Commented Nov 13, 2017 at 9:01

asherbret · Accepted Answer · 2017-11-13 11:29:54Z

5

Use the format function:

s = "alpha = 'a'"
exec """def my_func({}):
  return alpha""".format(s)

answered Nov 13, 2017 at 8:56

asherbret

6,0794 gold badges44 silver badges67 bronze badges

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

1 Answer 1