Version 1.1.0

Version 1.1.0
Previous release:Version 1.0.0


  • Frames with columns of type obj64 can now be saved into CSV. The values in the object column will be stringified upon saving. #3064

  • .replace() now supports numpy scalars. #3164

  • .to_numpy() now has an option to control memory layout of the resulting numpy array. #3275

  • column types returned by the method .sum() are now consistent with the ones returned by the function dt.sum(), i.e. int64 for void, boolean and integer columns; float32 for float32 columns; float64 for float64 columns. #2904

  • .to_csv() now has an option sep to control the field separator. #3337

  • Void columns can now be used with dt.sort() and In addition, datatable will now skip sorting any column that it knows contains constant values. #3088 #3104 #3108 #3109

  • Saving a frame with a void column into Jay no longer leads to a crash. #3074 #3099 #3246

  • Joining with void columns now works correctly. #3094

  • dt.sum() now works correctly when applied to the same column as #3110

  • Fixed a crash which could have occurred when sorting very long identical or nearly identical strings. #3134

  • It is now possible to sort all columns according to boolean flags in the reverse list #3168

  • Fixed support for .max_column_width option when rendering frames in Jupyter notebooks. #3160

  • Fixed a crash which in rare situations happened in .to_csv() due to multithreading. #3176

  • Fixed a crash in .to_pandas() when called on keyed frames. #3224

  • Fixed .to_csv() to quote missing values when quoting=”all” is specified. #3340

  • Fixed groupby behaviour on columns that contain missing values. #3331

  • Converting a column of void type into pandas now produces a pandas object column filled with Nones. Converting such column back into datatable produces a void column again. #3063

  • When creating Frame from a list of values, a floating-point nan value will now be treated as None. In particular, nans can now be safely mixed with values of other types, and a list consisting of only nans will turn into a Column of type void. #3083

  • Converting string or object columns to numpy no longer produces a masked array. Instead, we create a regular object array, filled with Nones in place of NAs. Similarly, converting a string or object column to pandas creates a Series with None values (instead of nans as before) in place of NAs. #3083



  • When reading Excel files, datetime fields will now be converted into time64 columns in the resulting frame.

  • When reading Excel files, forward slash, backslash, and their mix are supported as separators for specifying subpath. #3221

  • fread() now supports reading from public S3 buckets, when the source has a format of s3://bucket-name/key-name. #3302

  • Header detection heuristics has been improved in the case when some of the column names are missing. #3363

  • fread() will no longer fail while reading mostly empty files. #3055

  • fread() will no longer fail when reading excel files on Windows. #3178

  • Parameter tempdir is now honored for memory limited fread() operation. #3244

  • Parameter sep= in fread() will no longer accept values '-', '+', or '.'. Previously, these values were allowed but they produced errors during parsing. #3065


  • Fixed a bug in the LinearModel that in some cases resulted in the gradient and model coefficients blow up. #3234

  • Fixed undefined behaviour when LinearModel predicted on frames with missing values. #3260