Python read next()

When you do : f.readlines() you already read all the file so f.tell() will show you that you are in the end of the file, and doing f.next() will result in a StopIteration error.

Alternative of what you want to do is:

filne = "D:/testtube/testdkanimfilternode.txt"

with open(filne, 'r+') as f:
    for line in f:
        if line.startswith("anim "):
            print f.next() 
            # Or use next(f, '') to return <empty string> instead of raising a  
            # StopIteration if the last line is also a match.
            break

next() does not work in your case because you first call readlines() which basically sets the file iterator to point to the end of file.

Since you are reading in all the lines anyway you can refer to the next line using an index:

filne = "in"
with open(filne, 'r+') as f:
    lines = f.readlines()
    for i in range(0, len(lines)):
        line = lines[i]
        print line
        if line[:5] == "anim ":
            ne = lines[i + 1] # you may want to check that i < len(lines)
            print ' ne ',ne,'\n'
            break