hepconvert.merge_root

Defined in hepconvert.merge on line 240.

hepconvert.merge_root(destination, files, *, keep_branches=None, drop_branches=None, keep_trees=None, drop_trees=None, cut=None, expressions=None, progress_bar=None, fieldname_separator='_', title='', field_name=<function <lambda>>, initial_basket_capacity=10, resize_factor=10.0, counter_name=<function <lambda>>, step_size='100 MB', force=False, append=False, compression='zlib', compression_level=1, skip_bad_files=False)

Merges TTrees together, and adds values in histograms from local ROOT files, and writes them to a new ROOT file. Similar to ROOT’s hadd function.

Parameters:

  • destination (path-like) – Name of the output file or file path.

  • files (str or list of str) – List of local ROOT files to merge. May contain glob patterns.

  • keep_branches (list of str, str, or dict, optional) – To keep only certain branches and remove all others. To remove certain branches from all TTrees in the file, pass a list of names of branches to keep, wildcarding accepted (“Jet_*”). If removing branches from one of multiple trees, pass a dict of structure: {tree: [branch1, branch2]} to keep only branch1 and branch2 in ttree “tree”. Defaults to None. Command line option: --keep-branches.

  • drop_branches (list of str, str, or dict, optional) – To remove branches from all trees, pass a list of names of branches to remove. Wildcarding supported (“Jet_*”). If removing branches from one of multiple trees, pass a dict of structure: {tree: [branch1, branch2]} to remove branch1 and branch2 from TTree “tree”. Defaults to None. Command line option: --drop-branches.

  • keep_trees (str or list of str, optional) – To keep only certain a TTrees in a file, pass a list of names of trees to keep. All others will be removed. Defaults to None. Command line option: --keep-trees.

  • drop_trees (str or list of str, optional) – To remove a TTree from a file, pass a list of names of trees to remove. Defaults to None. Command line option: --drop-trees.

  • cut (None or str) – If not None, this expression filters all of the expressions.

  • expressions (None, str, or list of str) – Names of TBranches or aliases to convert to arrays or mathematical expressions of them. Uses the language to evaluate. If None, all TBranches selected by the filters are included.

  • progress_bar (Bool, tqdm.std.tqdm object) – Displays a progress bar. Can input a custom tqdm progress bar object, or set True for a default tqdm progress bar. Must have tqdm installed.

  • fieldname_separator (str, optional) – Character that separates TBranch names for columns, used for grouping columns (to avoid duplicate counters in ROOT file).

  • field_name (callable of str → str, optional) – Function to generate TBranch names for columns of an Awkward record array or a Pandas DataFrame.

  • initial_basket_capacity (int, optional) – Number of TBaskets that can be written to the TTree without rewriting the TTree metadata to make room. Command line option: --initial-basket-capacity.

  • resize_factor (float, optional) – When the TTree metadata needs to be rewritten, this specifies how many more TBasket slots to allocate as a multiplicative factor. Command line option: --resize-factor.

  • 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”. Recommended to be >100 kB. Command line option: --step-size.

  • force (bool, optional) – If True, overwrites destination file if it exists. Force and append cannot both be True. Command line option: --force.

  • append (bool, optional) – If True, appends data to an existing file. Force and append cannot both be True. Command line option: --append.

  • compression (str, optional) – Sets compression level for root file to write to. Can be one of “ZLIB”, “LZMA”, “LZ4”, or “ZSTD”. By default the compression algorithm is “ZLIB”. Command line option: --compression.

  • compression_level (int, optional) – Use a compression level particular to the chosen compressor. By default the compression level is 1. Command line option: --compression-level.

  • skip_bad_files (bool, optional) – If True, skips corrupt or non-existent files without exiting. Command line option: --skip-bad-files.

Example:

>>> hepconvert.merge_root("destination.root", ["file1.root", "file2.root"])

Command Line Instructions:

This function can be run from the command line. Use command

hepconvert merge [options] [OUT_FILE] [IN_FILES]