def _validate_usecols_names(usecols, names):
missing = [c for c in usecols if c not in names]<EOL>if len(missing) > <NUM_LIT:0>:<EOL><INDENT>raise ValueError(<EOL>"<STR_LIT>"<EOL>"<STR_LIT>".format(missing=missing)<EOL>)<EOL><DEDENT>return usecols<EOL>
Validates that all usecols are present in a given
list of names. If not, raise a ValueError that
shows what usecols are missing.

Parameters
----------
usecols : iterable of usecols
    The columns to validate are present in names.
names : iterable of names
    The column names to check against.

Returns
-------
usecols : iterable of usecols
    The `usecols` parameter if the validation succeeds.

Raises
------
ValueError : Columns were missing. Error message will list them.