def read_and_write(source, target): """Takes source file and target file, reads data from source file and is processed by iscommand function and written to target file.""" with open(source) as src: with open(target, "a") as tar: for line in src: contents = line.split() iscommand(contents, tar)

1. line is read from source file
2. line is split
3. split line is passed to iscommand function
4. line is written to target file