Difference between readlines() and iterating on a file object?

[Roy Smith]

Christopher T King <squirrel at WPI.EDU> wrote:
> Assuming you don't prematurely exit the for loop or access the file in 
> another manner while looping, both forms should give identical results.  
> Otherwise...

Well, there is a corner case if some external process is writing to the 
file while you're reading it.  The "in file.readlines():" version will 
get a snapshot of the file at the time you read it, while the "in file:" 
version will do a sequence of reads over time.

Not that I think this is what's going on in the OP's case, but it's 
something to be aware of.