Issue with lambda statement using python 3.5

[tbhadra]

Hi,
Lambda definition is-
get_path = lambda tiles, pos, path : path
Lambda call is-
sorted_by_path = sorted(labels, key=get_path)

Call to lambda with multiple positional arguments must be accompanied with arguments, but now there arises a error:-
TypeError: () missing 2 required positional arguments: 'pos' and 'path'

File name=geo_util.py

I don't know if anyone will respond to my issue.