numpy/numpy — pull request #5093 by styra (2014-09-21 08:46:33+00:00)
Title: Update function genfromtxt: add keywords nrows

Add keyword `nrows` to specify the number of rows to read.
1. We should not use keywords `nrows` and `skip_footer` in the same time. (As skip_footer require loading of the whold file, it seems a bit waste when we have already specified the number of rows to read. And the process for `invalid value` would be more complex with `skip_footer`.)
2. If there's not enough rows (less than nrows) to read, an exception would raise.

Add tests for the new behavior.