find unique timestamps per day

Question

I have a list (ie my_list) of 10000 elements. Each element is a dataframe that has 4 columns (namely: id, eventTime, name, value). I would like to iterate through the list of dataframes and find for every dataframe the amount of 'eventTime' per day. This is what I have so far.

values_per_day = []
for aa in my_list:
   find_values = my_list.eventTime.unique()
   values_per_day.append(find_values)

The error is:

AttributeError: 'list' object has no attribute 'eventTime'

Answer 1

您想使用变量aa而不是my_list ：

find_values = aa.eventTime.unique()