GH-15947: fixed test conditions when python object is tranforming to …

…H2O Frame and when import_file is loaded into H2O frame.

h2o-py/h2o/h2o.py

@@ -868,10 +868,18 @@ def parse_setup(raw_frames, destination_frame=None, header=0, separator=None, co
  if ind in skipped_columns:
  use_type[ind]=False
 
- if column_names is not None: # used when python object is converted to H2O Frame 
+ if column_names is not None: 
  if not isinstance(column_names, list): raise ValueError("col_names should be a list")
  if (skipped_columns is not None) and len(skipped_columns)>0:
- if len(column_names) != parse_column_len:
+ # when we are converting a python object to H2OFrame, column_names will include all columns despite
+ # skipped columns are specified. In this case, we need to make sure that 
+ # len(column_names)-len(skipped_columns)==parse_column_len
+ # When we are importing a file with skipped columns mentioned, column_names will only contain columns that
+ # are not skipped. Hence, in this case, we need to check len(column_names) == parse_column_len.
+ # To combine the two, correct parsing will have conditions len(column_names)-len(skipped_columns)==parse_column_len
+ # or len(column_names)==parse_column_len. Hence, we will raise an error when 
+ # not(len(column_names)-len(skipped_columns)==parse_column_len or len(column_names)==parse_column_len happened.
+ if not((len(column_names) == parse_column_len) or ((len(column_names)-len(skipped_columns))==parse_column_len)):
  raise ValueError(
  "length of col_names minus length of skipped_columns should equal the number of columns parsed: "
  "%d vs %d" % (len(column_names), parse_column_len))