Randomly presenting text stim from a single conditions file to multiple blocks

Windows 10.
PsychoPy version 1.90.1.

I have a single .csv file which contains trials from two conditions (20 in total, 10 in each condition).

I am attempting to present 4 trials (2 of each condition) per block - and thus I will need 5 blocks (4 trials x 5 blocks = 20 trials in total).

I am struggling to systematise this so that PsychoPy randomly presents 2 trials from condition 1 and 2 trials from condition 2, on every block. Of course, once trials have already been presented, I can’t have them presented again on a different block.

I have the PsychoPy text book and have looked on the ‘blocking’ Discourse page, but I can’t seem to find a section that is relevant to my issue. Unless, I have missed something?

Any help will be much appreciated. Thank you.