[v4 backport] Set ReadOnlyDirectory attributes when fSeekKeys == 0 (#661

)

* Set ReadOnlyDirectory attributes when fSeekKeys == 0

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* This B023 is okay (because it returns the last value seen; it doesn't allow the unbound value to change).

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* All of the B023 warnings are okay in this file.

I don't know why the v4 branch is complaining, whereas the v5 branch is not, and these should (ideally) be handled more centrally than tagging each use—that was probably done on the v5 branch. Nevertheless, we don't plan to develop this branch much more, just bug-fixes, so obfuscating it with "`# noqa: B023`" is not a problem here—just don't do it in the `main` (v5) branch!

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: Martin <ka_hei_martin_kwok@brown.edu>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Jim Pivarski <jpivarski@users.noreply.github.com>

src/uproot/_util.py

@@ -234,7 +234,7 @@ def regularize_rename(rename):
             def applyrules(x):
                 for matcher, trans in rules:
                     if matcher.search(x) is not None:
-                        return matcher.sub(trans, x)
+                        return matcher.sub(trans, x)  # noqa: B023
                 else:
                     return x
 

src/uproot/behaviors/TBranch.py

@@ -546,7 +546,7 @@ def lazy(
                 is_self.append(True)
 
                 def real_filter_branch(branch):
-                    return branch is original and filter_branch(branch)
+                    return branch is original and filter_branch(branch)  # noqa: B023
 
             else:
                 is_self.append(False)
@@ -614,17 +614,17 @@ def real_filter_branch(branch):
         )
 
         def foreach(start):
-            stop = min(start + entry_step, entry_stop)
+            stop = min(start + entry_step, entry_stop)  # noqa: B023
             length = stop - start
 
             fields = []
             names = []
             for key in common_keys:
-                branch = obj[key]
+                branch = obj[key]  # noqa: B023
 
-                interpretation = branchid_interpretation[branch.cache_key]
+                interpretation = branchid_interpretation[branch.cache_key]  # noqa: B023
                 form = interpretation.awkward_form(
-                    obj.file,
+                    obj.file,  # noqa: B023
                     {
                         "index_format": "i64",
                         "header": False,
@@ -637,7 +637,7 @@ def foreach(start):
                 )
 
                 generator = awkward.layout.ArrayGenerator(
-                    branch.array,
+                    branch.array,  # noqa: B023
                     (
                         None,
                         start,
@@ -654,7 +654,7 @@ def foreach(start):
                     length,
                 )
                 cache_key = "{}:{}:{}-{}:{}".format(
-                    branch.cache_key,
+                    branch.cache_key,  # noqa: B023
                     interpretation.cache_key,
                     start,
                     stop,
@@ -665,7 +665,7 @@ def foreach(start):
                     generator, cache=array_cache, cache_key=cache_key
                 )
                 fields.append(virtualarray)
-                names.append(key)
+                names.append(key)  # noqa: B023
 
             recordarray = awkward.layout.RecordArray(fields, names, length)
             partitions.append(recordarray)
@@ -3594,7 +3594,7 @@ def _get_dask_array(
                 is_self.append(True)
 
                 def real_filter_branch(branch):
-                    return branch is original and filter_branch(branch)
+                    return branch is original and filter_branch(branch)  # noqa: B023
 
             else:
                 is_self.append(False)
@@ -3671,13 +3671,13 @@ def delayed_get_array(ttree, key, start, stop):
                 dt, inner_shape = dt.subdtype
 
             def foreach(start):
-                stop = min(start + entry_step, entry_stop)
+                stop = min(start + entry_step, entry_stop)  # noqa: B023
                 length = stop - start
 
-                delayed_array = delayed_get_array(ttree, key, start, stop)
-                shape = (length,) + inner_shape
-                dask_arrays.append(
-                    da.from_delayed(delayed_array, shape=shape, dtype=dt)
+                delayed_array = delayed_get_array(ttree, key, start, stop)  # noqa: B023
+                shape = (length,) + inner_shape  # noqa: B023
+                dask_arrays.append(  # noqa: B023
+                    da.from_delayed(delayed_array, shape=shape, dtype=dt)  # noqa: B023
                 )
 
             for start in range(entry_start, entry_stop, entry_step):

src/uproot/reading.py

@@ -1405,7 +1405,8 @@ def __init__(self, path, cursor, context, file, parent):
         if self._fSeekKeys == 0:
             self._header_key = None
             self._keys = []
-
+            self._keys_lookup = {}
+            self._len = None
         else:
             keys_start = self._fSeekKeys
             keys_stop = min(keys_start + self._fNbytesKeys + 8, file.fEND)