Question

In Python, I’d like to create a string block with embedded expressions.
In Ruby, the code looks like this:

def get_val
  100
end

def testcode
s=<<EOS

This is a sample string that references a variable whose value is: #{get_val}
Incrementing the value: #{get_val + 1}

EOS
  puts s
end

testcode

Answer 1

Update: since Python 3.6, there are formatted string literals (f-strings) which enable a literal string interpolation: f"..{get_val()+1}..."

---

If you need more than just a simple string formatting provided by str.format() and % then templet module could be used to insert Python expressions:

from templet import stringfunction

def get_val():
    return 100

@stringfunction
def testcode(get_val):
    """
    This is a sample string
    that references a function whose value is: ${ get_val() }
    Incrementing the value: ${ get_val() + 1 }
    """

print(testcode(get_val))

Output

This is a sample string
that references a function whose value is: 100
Incrementing the value: 101

Python Templating with @stringfunction.