join#

astropy.table.join(left, right, keys=None, join_type='inner', *, keys_left=None, keys_right=None, keep_order=False, uniq_col_name='{col_name}_{table_name}', table_names=['1', '2'], metadata_conflicts='warn', join_funcs=None)[source]#

Perform a join of the left table with the right table on specified keys.

Parameters:
leftTableastropy:-like object

Left side table in the join. If not a Table, will call Table(left)

rightTableastropy:-like object

Right side table in the join. If not a Table, will call Table(right)

keyspython:str or python:list of python:str

Name(s) of column(s) used to match rows of left and right tables. Default is to use all columns which are common to both tables.

join_typepython:str

Join type (‘inner’ | ‘outer’ | ‘left’ | ‘right’ | ‘cartesian’), default is ‘inner’

keys_leftpython:str or python:list of python:str or python:list of column-like, optional

Left column(s) used to match rows instead of keys arg. This can be be a single left table column name or list of column names, or a list of column-like values with the same lengths as the left table.

keys_rightpython:str or python:list of python:str or python:list of column-like, optional

Same as keys_left, but for the right side of the join.

keep_order: bool, optional

By default, rows are sorted by the join keys. If True, preserve the order of rows from the left table for “inner” or “left” joins, or from the right table for “right” joins. For other join types this argument is ignored except that a warning is issued if keep_order=True.

uniq_col_namepython:str or python:None

String generate a unique output column name in case of a conflict. The default is ‘{col_name}_{table_name}’.

table_namespython:list of python:str or python:None

Two-element list of table names used when generating unique output column names. The default is [‘1’, ‘2’].

metadata_conflictspython:str
How to proceed with metadata conflicts. This should be one of:

  • 'silent': silently pick the last conflicting meta-data value

  • 'warn': pick the last conflicting meta-data value, but emit a warning (default)

  • 'error': raise an exception.

join_funcspython:dict, python:None

Dict of functions to use for matching the corresponding key column(s). See join_skycoord for an example and details.

Returns:
joined_tableTable object

New table containing the result of the join operation.