# uproot.models.RNTuple.RField

Defined in uproot.models.RNTuple on line 1472.

Inheritance order:
uproot.behaviors.RNTuple.HasFields `collections.abc.Mapping` `collections.abc.Collection` `collections.abc.Sized` `collections.abc.Iterable` `collections.abc.Container`

class uproot.models.RNTuple.RField(fid, ntuple)

## name

RField.name

  Name of the `RField`.

## description

RField.description

  Description of the `RField`.

## typename

RField.typename

  The C++ typename of the `RField`.

## record

RField.record

  The field record of the `RField`.

## is_anonymous

RField.is_anonymous

  There are some anonymous fields in the RNTuple specification that we hide from the user to simplify the interface. These are fields named _0 that are children of a collection, variant, or atomic field.

  All children fields of variants are ignored, since they cannot be accessed directly in a consistent manner. They can only be accessed through the parent variant field.

## is_ignored

RField.is_ignored

  _i` (for i=0,1,2,…) that encode class hierarchy. These are not useful in Uproot, so they are ignored.

  Type:

    There are some fields in the RNTuple specification named `

## parent

RField.parent

  The parent of this `RField`.

## index

RField.index

  Integer position of this `RField` in its parent’s list of fields.

## field_id

RField.field_id

  The field ID of this `RField` in the RNTuple.

## top_level

RField.top_level

  True if this is a top-level field, False otherwise.

## array

RField.array(entry_start=None, entry_stop=None, *, decompression_executor=None, array_cache='inherit', library='ak', interpreter='cpu', backend='cpu', ak_add_doc=False, interpretation=None, interpretation_executor=None)
  Parameters:

    - entry_start (None or int) – The first entry to include. If None, start at zero. If negative, count from the end, like a Python slice.

    - entry_stop (None or int) – The first entry to exclude (i.e. one greater than the last entry to include). If None, stop at num_entries. If negative, count from the end, like a Python slice.

    - decompression_executor (None or Executor with a `submit` method) – The executor that is used to decompress `RPages`; if None, the file’s decompression_executor is used. (Not implemented yet.)

    - array_cache ("inherit", None, MutableMapping, or memory size) – Cache of arrays; if “inherit”, use the file’s cache; if None, do not use a cache; if a memory size, create a new cache of this size. (Not implemented yet.)

    - library (str or uproot.interpretation.library.Library) – The library that is used to represent arrays. Options are `"np"` for NumPy, `"ak"` for Awkward Array, and `"pd"` for Pandas.

    - ak_add_doc (bool | dict) – If True and `library="ak"`, add the RField `description` to the Awkward `__doc__` parameter of the array. if dict = {key:value} and `library="ak"`, add the RField `value` to the Awkward `key` parameter of the array.

    - interpretation (None) – This argument is not used and is only included for now for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

    - interpretation_executor (None) – This argument is not used and is only included for now for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns the `RField` data as an array.

  For example:

      >>> field = ntuple["my_field"]
      >>> array = field.array()
      >>> array
      <Array [-41.2, 35.1, 35.1, ... 32.4, 32.5] type='2304 * float64'>

  See also arrays to read multiple `RFields` into a group of arrays or an array-group.

## ntuple

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.ntuple

  The uproot.models.RNTuple.RNTuple that this uproot.models.RNTuple.HasFields is part of.

## num_entries

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.num_entries

  The number of entries in the `RNTuple`.

## fields

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.fields

  The list of uproot.models.RNTuple.RField directly under this uproot.models.RNTuple.RNTuple or uproot.models.RNTuple.RField (i.e. not recursive).

## path

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.path

  The full path of the field in the uproot.models.RNTuple.RNTuple. When it is the `RNTuple` itself, this is `"."`.

  Note that this is not the full path within the ROOT file.

## to_akform

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.to_akform(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, ak_add_doc=False, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - ak_add_doc (bool | dict) – If True and `library="ak"`, add the RField `description` to the Awkward `__doc__` parameter of the array. if dict = {key:value} and `library="ak"`, add the RField `value` to the Awkward `key` parameter of the array.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns a 2-tuple where the first entry is the Awkward Form with the structure of the data in the `RNTuple` or `RField`, and the second entry is the relative path of the requested RField. The second entry is needed in cases where the requested RField is a subfield of a collection, which requires constructing the form with information about the parent field.

## arrays

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.arrays(expressions=None, cut=None, *, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, aliases=None, language=uproot.language.python.PythonLanguage(), entry_start=None, entry_stop=None, decompression_executor=None, array_cache='inherit', library='ak', backend='cpu', interpreter='cpu', ak_add_doc=False, how=None, interpretation_executor=None, filter_branch=uproot._util.unset)
  Parameters:

    - expressions (None, str, or list of str) – Names of `RFields` or aliases to convert to arrays or mathematical expressions of them. Uses the `language` to evaluate. If None, all `RFields` selected by the filters are included. (Not implemented yet.)

    - cut (None or str) – If not None, this expression filters all of the `expressions`. (Not implemented yet.)

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. If the function returns False or None, the `RField` is excluded; if the function returns True, it is included.

    - aliases (None or dict of str → str) – Mathematical expressions that can be used in `expressions` or other aliases. Uses the `language` engine to evaluate. (Not implemented yet.)

    - language (uproot.language.Language) – Language used to interpret the `expressions` and `aliases`. (Not implemented yet.)

    - entry_start (None or int) – The first entry to include. If None, start at zero. If negative, count from the end, like a Python slice.

    - entry_stop (None or int) – The first entry to exclude (i.e. one greater than the last entry to include). If None, stop at num_entries. If negative, count from the end, like a Python slice.

    - decompression_executor (None or Executor with a `submit` method) – The executor that is used to decompress `RPages`; if None, the file’s decompression_executor is used. (Not implemented yet.)

    - array_cache ("inherit", None, MutableMapping, or memory size) – Cache of arrays; if “inherit”, use the file’s cache; if None, do not use a cache; if a memory size, create a new cache of this size. (Not implemented yet.)

    - library (str or uproot.interpretation.library.Library) – The library that is used to represent arrays. Options are `"np"` for NumPy, `"ak"` for Awkward Array, and `"pd"` for Pandas. (Not implemented yet.)

    - backend (str) – The backend Awkward Array will use.

    - interpreter (str) – If “cpu” will use cpu to interpret raw data. If “gpu” and `backend="cuda"` will use KvikIO bindings to CuFile and nvCOMP to interpret raw data on gpu if available.

    - ak_add_doc (bool | dict) – If True and `library="ak"`, add the RField `description` to the Awkward `__doc__` parameter of the array. if dict = {key:value} and `library="ak"`, add the RField `value` to the Awkward `key` parameter of the array.

    - how (None, str, or container type) – Library-dependent instructions for grouping. The only recognized container types are `tuple`, `list`, and `dict`. Note that the container type itself must be passed as `how`, not an instance of that type (i.e. `how=tuple`, not `how=()`).

    - interpretation_executor (None) – This argument is not used and is only included for now for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

    - filter_branch – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns a group of arrays from the `RNTuple`.

  For example:

      >>> my_ntuple.arrays()
      <Array [{my_vector: [1, 2]}, {...}] type='2 * {my_vector: var * int64}'>

  See also uproot.behaviors.RNTuple.HasFields.array to read a single `RField` as an array.

  See also iterate to iterate over the array in contiguous ranges of entries.

## iterate

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.iterate(expressions=None, cut=None, *, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, aliases=None, language=uproot.language.python.PythonLanguage(), entry_start=None, entry_stop=None, step_size='100 MB', decompression_executor=None, library='ak', backend='cpu', interpreter='cpu', ak_add_doc=False, how=None, report=False, interpretation_executor=None, filter_branch=uproot._util.unset)
  Parameters:

    - expressions (None, str, or list of str) – Names of `RFields` or aliases to convert to arrays or mathematical expressions of them. Uses the `language` to evaluate. If None, all `RFields` selected by the filters are included. (Not implemented yet.)

    - cut (None or str) – If not None, this expression filters all of the `expressions`. (Not implemented yet.)

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `EFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool, or None) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. If the function returns False or None, the `RField` is excluded; if the function returns True, it is included.

    - aliases (None or dict of str → str) – Mathematical expressions that can be used in `expressions` or other aliases. Uses the `language` engine to evaluate. (Not implemented yet.)

    - language (uproot.language.Language) – Language used to interpret the `expressions` and `aliases`. (Not implemented yet.)

    - entry_start (None or int) – The first entry to include. If None, start at zero. If negative, count from the end, like a Python slice.

    - entry_stop (None or int) – The first entry to exclude (i.e. one greater than the last entry to include). If None, stop at num_entries. If negative, count from the end, like a Python slice.

    - step_size (int or str) – If an integer, the maximum number of entries to include in each iteration step; if a string, the maximum memory size to include. The string must be a number followed by a memory unit, such as “100 MB”.

    - decompression_executor (None or Executor with a `submit` method) – The executor that is used to decompress `RPages`; if None, the file’s decompression_executor is used. (Not implemented yet.)

    - library (str or uproot.interpretation.library.Library) – The library that is used to represent arrays. Options are `"np"` for NumPy, `"ak"` for Awkward Array, and `"pd"` for Pandas. (Not implemented yet.)

    - ak_add_doc (bool | dict) – If True and `library="ak"`, add the RField `description` to the Awkward `__doc__` parameter of the array. if dict = {key:value} and `library="ak"`, add the RField `value` to the Awkward `key` parameter of the array. (Not implemented yet.)

    - how (None, str, or container type) – Library-dependent instructions for grouping. The only recognized container types are `tuple`, `list`, and `dict`. Note that the container type itself must be passed as `how`, not an instance of that type (i.e. `how=tuple`, not `how=()`).

    - report (bool) – If True, this generator yields (arrays, uproot.behaviors.TBranch.Report) pairs; if False, it only yields arrays. The report has data about the `TFile`, `RNTuple`, and global and local entry ranges. (Not implemented yet.)

    - interpretation_executor (None) – This argument is not used and is only included for now for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Iterates through contiguous chunks of entries from the `RNTuple`.

  For example:

      >>> for array in rntuple.iterate(filter_name=["x", "y"], step_size=100):
      ...     # each of the following have 100 entries
      ...     array["x"], array["y"]

  See also arrays to read everything in a single step, without iteration.

  See also uproot.iterate to iterate over many files.

## keys

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.keys(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, full_paths=True, ignore_duplicates=False, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - full_paths (bool) – If True, include the full path to each subfield with periods (`.`); otherwise, use the descendant’s name as the output name.

    - ignore_duplicates (bool) – If True, return a set of the keys; otherwise, return the full list of keys.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns the names of the subfields as a list of strings.

## values

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.values(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns the subfields as a list of uproot.behaviors.RField.RField.

  (Note: with `recursive=False`, this is the same as uproot.behaviors.TBranch.HasFields.fields.)

## items

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.items(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, full_paths=True, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - full_paths (bool) – If True, include the full path to each subfield with periods (`.`); otherwise, use the descendant’s name as the output name.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns (name, field) pairs of the subfields as a list of 2-tuples of (str, uproot.behaviors.RField.RField).

## typenames

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.typenames(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, full_paths=True, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - full_paths (bool) – If True, include the full path to each subfield with periods (`.`); otherwise, use the descendant’s name as the output name.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns (name, typename) pairs of the subfields as a dict of str → str.

## iterkeys

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.iterkeys(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, full_paths=True, ignore_duplicates=False, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - full_paths (bool) – If True, include the full path to each subfield with periods (`.`); otherwise, use the descendant’s name as the output name.

    - ignore_duplicates (bool) – If True, return a set of the keys; otherwise, return the full list of keys.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns the names of the subfields as an iterator over strings.

## itervalues

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.itervalues(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns the subfields as an iterator over uproot.behaviors.RField.RField.

  (Note: with `recursive=False`, this is the same as uproot.behaviors.RField.HasFields.fields.)

## iteritems

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.iteritems(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, full_paths=True, ignore_duplicates=False, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - full_paths (bool) – If True, include the full path to each subfield with periods (`.`); otherwise, use the descendant’s name as the output name.

    - ignore_duplicates (bool) – If True, return a set of the keys; otherwise, return the full list of keys.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns (name, field) pairs of the subfields as an iterator over 2-tuples of (str, uproot.behaviors.RField.RField).

## itertypenames

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.itertypenames(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, full_paths=True, filter_branch=uproot._util.unset)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select ``RFields``s by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, descend into any nested subfields. If False, only return the names of the top fields.

    - full_paths (bool) – If True, include the full path to each subfield with periods (`.`); otherwise, use the descendant’s name as the output name.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns (name, typename) pairs of the subfields as an iterator over 2-tuples of (str, str).

## num_entries_for

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.num_entries_for(memory_size, expressions=None, cut=None, *, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, aliases=None, language=uproot.language.python.PythonLanguage(), entry_start=None, entry_stop=None, filter_branch=uproot._util.unset)
  Parameters:

    - memory_size (int or str) – An integer is interpreted as a number of bytes and a string must be a number followed by a unit, such as “100 MB”.

    - expressions (None, str, or list of str) – Names of `RFields` or aliases to convert to arrays or mathematical expressions of them. Uses the `language` to evaluate. If None, all `RFields` selected by the filters are included. (Not implemented yet.)

    - cut (None or str) – If not None, this expression filters all of the `expressions`. (Not implemented yet.)

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RField.RField → bool, or None) – A filter to select `RFields` using the full uproot.models.RField.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - aliases (None or dict of str → str) – Mathematical expressions that can be used in `expressions` or other aliases. Uses the `language` engine to evaluate.

    - language (uproot.language.Language) – Language used to interpret the `expressions` and `aliases`.

    - entry_start (None or int) – The first entry to include. If None, start at zero. If negative, count from the end, like a Python slice.

    - entry_stop (None or int) – The first entry to exclude (i.e. one greater than the last entry to include). If None, stop at num_entries. If negative, count from the end, like a Python slice.

    - filter_branch (None or function of uproot.models.RNTuple.RField → bool) – An alias for `filter_field` included for compatibility with software that was used for uproot.TBranch. This argument should not be used and will be removed in a future version.

  Returns an approximate step size as a number of entries to read a given `memory_size` in each step.

  This method does not actually read the `RField` data or compute any expressions to arrive at its estimate. It only uses metadata from the already-loaded `RNTuple`; it only needs `language` to parse the expressions, not to evaluate them.

  This is the algorithm that iterate uses to convert a `step_size` expressed in memory units into a number of entries.

## show

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.show(*, filter_name=<function no_filter>, filter_typename=<function no_filter>, filter_field=<function no_filter>, recursive=True, max_width=80, stream=<_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>, **kwargs)
  Parameters:

    - filter_name (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by name.

    - filter_typename (None, glob string, regex string in `"/pattern/i"` syntax, function of str → bool, or iterable of the above) – A filter to select `RFields` by type.

    - filter_field (None or function of uproot.models.RNTuple.RField → bool, or None) – A filter to select `RFields` using the full uproot.models.RNTuple.RField object. The `RField` is included if the function returns True, excluded if it returns False.

    - recursive (bool) – If True, recursively descend into subfields.

    - max_width (int) – Maximum number of characters to display in a line.

    - stream (object with a `write(str)` method) – Stream to write the output to.

  Interactively display the `RFields`.

  For example,

      >>> my_ntuple.show()
      my_ntuple (ROOT::RNTuple)
      Description: The description of the ntuple
      ├─ my_int (std::int64_t)
      │  Description: The description of the field
      ├─ jagged_list (std::vector<std::int64_t>)
      ├─ nested_list (std::vector<std::vector<std::int64_t>>)
      ├─ struct (MyStruct)
      │  ├─ x (std::int64_t)
      │  └─ y (std::int64_t)
      └─ other_struct (OtherStruct)
          ├─ a (SubStruct)
          │  Description: The description of the subfield
          │  ├─ x (std::int64_t)
          │  └─ y (std::int64_t)
          └─ b (std::int64_t)

## source

Inherited from uproot.behaviors.RNTuple.HasFields.

RField.source

  Returns the associated source of data for this container, if it exists

  Returns: uproot.source.chunk.Source or None