Is it possible to modify lines in a file in-place?

Question

Is it possible to parse a file line by line, and edit a line in-place while going through the lines?

Answer 1

fileinput module has very ugly API, I find beautiful module for this task - in_place, example for Python 3:

import in_place

with in_place.InPlace('data.txt') as file:
    for line in file:
        line = line.replace('test', 'testZ')
        file.write(line)

main difference from fileinput:

• Instead of hijacking sys.stdout, a new filehandle is returned for writing.
• The filehandle supports all of the standard I/O methods, not just readline().

Some useful notes from @rocksNwaves placed in comment