Reading an object with colon in its name

[plasorak]

Hi all,

I'm trying to read an object which has colon in its name. So doing something like:
data = up.open("path/to/file.root")["that:histo:with:colon:in:the:middle"]
That exits with the following error:

    step = step[item]
  File "/usr/local/lib/python3.9/site-packages/uproot/reading.py", line 1962, in __getitem__
    step = step[item]
  File "/usr/local/lib/python3.9/site-packages/uproot/reading.py", line 1962, in __getitem__
    step = step[item]
  [Previous line repeated 992 more times]
  File "/usr/local/lib/python3.9/site-packages/uproot/reading.py", line 1945, in __getitem__
    if ":" in item and item not in step:
  File "/usr/local/lib/python3.9/site-packages/uproot/reading.py", line 1810, in __contains__
    self.key(where)
  File "/usr/local/lib/python3.9/site-packages/uproot/reading.py", line 1887, in key
    where = uproot._util.ensure_str(where)
  File "/usr/local/lib/python3.9/site-packages/uproot/_util.py", line 72, in ensure_str
    if not py2 and isinstance(x, bytes):
RecursionError: maximum recursion depth exceeded while calling a Python object

How would I do that?
Thanks.

[jpivarski]

Short answer: put the file name in a pathlib.Path. These are not colon-split. In this mode, you can't put the object path in the same string, it has to be uproot.open(pathlib.Path(filename))[object_path_here].

For more details, the thread where we discussed the design of this is #79.

[plasorak]

That works for the file name, but not for the object path right?

[jpivarski]

Oh, I missed that. I hadn't realized that colons would be legal characters in objects—ah, it's TBranches that use colon as part of its constructor syntax.

Fortunately (really lucky, actually, the TDirectory.key method (here) doesn't parse colons, so you can do

data = uproot.open("path/to/file.root").key("that:histo:with:colon:in:the:middle").get()