If the string is fixed you can simply use:
if line.startswith("Path="):
return line[5:]
which gives you everything from position 5 on in the string (a string is also a sequence so these sequence operators work here, too).
Or you can split the line at the first =
:
if "=" in line:
param, value = line.split("=",1)
Then param is "Path" and value is the rest after the first =.