uproot.iterate usage

[bojohnson5]

I'm able to open a ROOT file and use as needed with uproot.open but if I try reading multiple files with uproot.iterate I get an error: NotImplementedError: memberwise serialization of AsArray. I'm unsure of why I can use open and read in data but not iterate. Could this be unique to my particular ROOT files that have custom classes implemented in them?

[bojohnson5]

It appears if I filter out the custom classes I get the behavior I'm looking for. Something like uproot.iterate("<files>:<tree>", filter_name="<non-custom branches>") will work.

[pfackeldey]

Afaik, uproot implements the most common ROOT classes in python such that they can be interpreted. Custom classes do not necessarily have such an implementation in uproot and thus can't be understood.

This issue here arises because uproot.open doesn't read, it just opens the file, whereas uproot.iterate will also read.

@ianna can probably provide more details or correct me here.

[bojohnson5]

Thanks for the response. After changing what I did from above and your comment here helped clarify how the iterate function works!