Is it safe to mix readline() and line iterators in python file processing?

Question

Is it safe to read some lines with readline() and also use for line in file, and is it guaranteed to use the same file position?

Usually, I

Answer 1

This works out well in the long run. It ignores the fact that you're processing a file, and works with any sequence. Also, having the explicit iterator object (rdr) hanging around allows you to skip lines inside the body of for loop without messing anything up.

with open("myfile.txt","r") as source:
    rdr= iter(source)
    heading= next(rdr)
    for line in rdr:
        process( line )