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)

The function read_and_write takes two arguments source and target. It creates a file object src and a file object tar. For each line in the src it splits the line into words and assigns a variable to the split line called contents. Then it calls the iscommand function and passes the contents and tar arguments.