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new (function)
==============
Create a new empty Loom file and return it as a context manager.
.. autofunction:: loompy.new
The ``new()`` function is especially useful when you want to combine data from multiple sources. You would
first create an empty Loom file, then add data to it incrementally. For example, using ``new()`` and ``scan()``:
.. code:: python
with loompy.new(out_file) as dsout: # Create a new, empty, loom file
for f in input_files: # Loop over a list of input Loom files
with loompy.connect(f) as ds:
totals = ds.map([np.sum], axis=1)[0] # Calculate the total molecule count for each cell
cells = np.where(totals > 500)[0] # Select the cells that passed QC (totals > 500)
for (ix, selection, view) in ds.scan(items=cells, axis=1, key="Accession"):
dsout.add_columns(view.layers, col_attrs=view.ca, row_attrs=view.ra)
Note the use of ``key=="Accession"`` which makes ``scan()`` sort the rows of each file by the row
attribute ``Accession``, ensuring that the resulting output is in a consistent order.
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