What does this syntax mean in Python?

Question

What does the comma in the declaration below mean? Does it define two variables at once?

resp, content = client.request(request_token_url, \"GET\")

Answer 1

That's called tuple unpacking. In python, you can unpack tuples like this:

a, b = (1, 2)

See that on the right we have a tuple, packing values, and they are automatically "distributed" to the objects on the left.

If a function returns a tuple, in can be unpacked as well:

>>> def t():
...     return (1, 2)
... 
>>> a, b = t()
>>> a
1
>>> b
2

That's what's happening in your code.