My text editor places a comment block at the top of each source file with 
a block of information about the author, the project, license, etc. One 
(rather pointless) line of this block looks like

 # FILE: "somefile.py"

The re in `_find_lineno()` misinterprets this line as the beginning of the 
docstring. I believe the attached patch maintains the spirit of the re, 
while avoiding this false positive.

I could not reproduce the behaviour you describe.
Could you provide a test case? That fails with the current code and is 
fixed after applying your patch.

(BTW, the r.e. should be a raw string literal, even the original one)

Out of date.