python: i need help creating the program below that reads a file and writes a file at the end. comments could be very helpful

Given: A file containing at most 1000 lines.

Return: A file containing all the even-numbered lines from the original file. Assume 1-based numbering of lines.

Sample Dataset

Bravely bold Sir Robin rode forth from Camelot Yes, brave Sir Robin turned about He was not afraid to die, O brave Sir Robin And gallantly he chickened out He was not at all afraid to be killed in nasty ways Bravely talking to his feet Brave, brave, brave, brave Sir Robin He beat a very brave retreat 

Sample Output

Yes, brave Sir Robin turned about And gallantly he chickened out Bravely talking to his feet He beat a very brave retreat