Templating with both local and global variables using Python `format`

Question

It's nice in Python to be able to write code like 'Foo bar {some_var} baz'.format(**locals()). Depending on what other languages you're used to, you may already find that a bit verbose, but what about when you want to pull in global variables as well? The best I can do is this:

GLOBAL_VAR = "Hello"

def func():
    local_var = "world!"
    print("{GLOBAL_VAR} {local_var}".format(**dict(locals(), **globals())))

func()

That format(**dict(locals(), **globals()))) is quite a mouthful. Is there a more succinct way to do string templating when I want to replace both global and local variables by name?

Answer 1

In 3.6, you'll finally get syntax-level support for string interpolation:

f"{GLOBAL_VAR} {local_var}" # No format(), locals(), or globals()!

As of this writing, 3.6 isn't here yet, though.

In 3.5, you can unpack two dicts for keyword arguments in the same function call:

"{GLOBAL_VAR} {local_var}".format(**globals(), **locals())

3.5 is here, but maybe you're not using it, or you have to support older Python versions.

In Python versions below 3.5, there isn't really anything more succinct.