This is in addition to a similar thread pointing out the inconsistencies in five-minute data that I had posted two months back https://kite.trade/forum/discussion/comment/17863/#Comment_17863. Although I have found (painful) workarounds to deal with inconsistencies in the data downloaded from zerodha, I sometimes wonder why even simple problems which can be easily fixed (and for which now I've routinely scan for in my code), are not looked at.
One such simple problem is that duplicate entries in the 1 day data. One of the main dates that seem to happen in several instruments is 2015-12-31. Its there in ITC, RELIANCE (and I list about 20 more stocks at least). I hope at some point of time you can just consider adding a few lines of code scan for duplicates. There are more such in 1 day data 2009-04-09.
Similarly, in five-minute data, there are hundreds of instances when the timestamp at the beginning of day is 09:15:00 or 09:15:01 and so on.. Also, the volume is 0 in several instances in the first five minutes. (And this includes data after 2017 also because in the earlier case, I was told that in 2015, the data may be inconsistent).
not here to make zerodha look bad. I'm just grateful that at least there are some steps a brokerage has taken to help the retail traders. And I hope that such messages help to improve the service for all of us.