It's definitely a bag of dicks. Most of the things I've encountered in Qt are not intuitive at all and you have a mixture of deprecated and non-deprecated calls which are not obvious. Qt people aren't really from a financial background either, a simple QDateTime axis seems to plot everything, including the weekends when there are no data points on the input (so you have gaps on the x axis). Why? I have no idea.
To be fair, matplotlib does that as well but it's dumb easy to get around it:
Code:
plt.xticks(x.index)
plt.plot(x.close.values)
With Qt Charts, you have to pray to God your chart doesn't go blank with the latest changes.