Cudf

New Features

- PR 1194 Implement overloads for CUDA atomic operations
- PR 1292 Implemented Bitwise binary ops AND, OR, XOR (&, |, ^)
- PR 1235 Add GPU-accelerated Parquet Reader
- PR 1335 Added local_dict arg in `DataFrame.query()`.

Improvements

- PR 1202 Simplify README.md
- PR 1149 CSV Reader: Change convertStrToValue() functions to `__device__` only
- PR 1238 Improve performance of the CUDA trie used in the CSV reader
- PR 1278 Update CONTRIBUTING for new conda environment yml naming conventions
- PR 1163 Refactored UnaryOps. Reduced API to two functions: `gdf_unary_math` and `gdf_cast`. Added `abs`, `-`, and `~` ops. Changed bindings to Cython
- PR 1284 Update docs version
- PR 1287 add exclude argument to cudf.select_dtype function
- PR 1286 Refactor some of the CSV Reader kernels into generic utility functions
- PR 1291 fillna in `Series.to_gpu_array()` and `Series.to_array()` can accept the scalar too now.

Bug Fixes

- PR 1233 Fix dtypes issue while adding the column to `str` dataframe.
- PR 1254 CSV Reader: fix data type detection for floating-point numbers in scientific notation
- PR 1289 Fix looping over each value instead of each category in concatenation
- PR 1293 Fix Inaccurate error message in join.pyx
- PR 1308 Add atomicCAS overload for `int8_t`, `int16_t`
- PR 1317 Fix catch polymorphic exception by reference in ipc.cu
- PR 1325 Fix dtype of null bitmasks to int8
- PR 1326 Update build documentation to use -DCMAKE_CXX11_ABI=ON
- PR 1334 Add "na_position" argument to CategoricalColumn sort_by_values
- PR 1321 Fix out of bounds warning when checking Bzip2 header

New Features

- PR 760 Raise `FileNotFoundError` instead of `GDF_FILE_ERROR` in `read_csv` if the file does not exist
- PR 539 Add Python bindings for replace function
- PR 823 Add Doxygen configuration to enable building HTML documentation for libcudf C/C++ API
- PR 807 CSV Reader: Add byte_range parameter to specify the range in the input file to be read
- PR 857 Add Tail method for Series/DataFrame and update Head method to use iloc
- PR 858 Add series feature hashing support
- PR 871 CSV Reader: Add support for NA values, including user specified strings
- PR 893 Adds PyArrow based parquet readers / writers to Python, fix category dtype handling, fix arrow ingest buffer size issues
- PR 867 CSV Reader: Add support for ignoring blank lines and comment lines
- PR 887 Add Series digitize method
- PR 895 Add Series groupby
- PR 898 Add DataFrame.groupby(level=0) support
- PR 920 Add feather, JSON, HDF5 readers / writers from PyArrow / Pandas
- PR 888 CSV Reader: Add prefix parameter for column names, used when parsing without a header
- PR 913 Add DLPack support: convert between cuDF DataFrame and DLTensor
- PR 939 Add ORC reader from PyArrow
- PR 918 Add Series.groupby(level=0) support
- PR 906 Add binary and comparison ops to DataFrame
- PR 958 Support unary and binary ops on indexes
- PR 964 Add `rename` method to `DataFrame`, `Series`, and `Index`
- PR 985 Add `Series.to_frame` method
- PR 985 Add `drop=` keyword to reset_index method
- PR 994 Remove references to pygdf
- PR 990 Add external series groupby support
- PR 988 Add top-level merge function to cuDF
- PR 992 Add comparison binaryops to DateTime columns
- PR 996 Replace relative path imports with absolute paths in tests
- PR 995 CSV Reader: Add index_col parameter to specify the column name or index to be used as row labels
- PR 1004 Add `from_gpu_matrix` method to DataFrame
- PR 997 Add property index setter
- PR 1007 Replace relative path imports with absolute paths in cudf
- PR 1013 select columns with df.columns
- PR 1016 Rename Series.unique_count() to nunique() to match pandas API
- PR 947 Prefixsum to handle nulls and float types
- PR 1029 Remove rest of relative path imports
- PR 1021 Add filtered selection with assignment for Dataframes
- PR 872 Adding NVCategory support to cudf apis
- PR 1052 Add left/right_index and left/right_on keywords to merge
- PR 1091 Add `indicator=` and `suffixes=` keywords to merge
- PR 1107 Add unsupported keywords to Series.fillna
- PR 1032 Add string support to cuDF python
- PR 1136 Removed `gdf_concat`
- PR 1153 Added function for getting the padded allocation size for valid bitmask
- PR 1148 Add cudf.sqrt for dataframes and Series
- PR 1159 Add Python bindings for libcudf dlpack functions
- PR 1155 Add __array_ufunc__ for DataFrame and Series for sqrt
- PR 1168 to_frame for series accepts a name argument

Improvements

- PR 1218 Add dask-cudf page to API docs
- PR 892 Add support for heterogeneous types in binary ops with JIT
- PR 730 Improve performance of `gdf_table` constructor
- PR 561 Add Doxygen style comments to Join CUDA functions
- PR 813 unified libcudf API functions by replacing gpu_ with gdf_
- PR 822 Add support for `__cuda_array_interface__` for ingest
- PR 756 Consolidate common helper functions from unordered map and multimap
- PR 753 Improve performance of groupby sum and average, especially for cases with few groups.
- PR 836 Add ingest support for arrow chunked arrays in Column, Series, DataFrame creation
- PR 763 Format doxygen comments for csv_read_arg struct
- PR 532 CSV Reader: Use type dispatcher instead of switch block
- PR 694 Unit test utilities improvements
- PR 878 Add better indexing to Groupby
- PR 554 Add `empty` method and `is_monotonic` attribute to `Index`
- PR 1040 Fixed up Doxygen comment tags
- PR 909 CSV Reader: Avoid host->device->host copy for header row data
- PR 916 Improved unit testing and error checking for `gdf_column_concat`
- PR 941 Replace `numpy` call in `Series.hash_encode` with `numba`
- PR 942 Added increment/decrement operators for wrapper types
- PR 943 Updated `count_nonzero_mask` to return `num_rows` when the mask is null
- PR 952 Added trait to map C++ type to `gdf_dtype`
- PR 966 Updated RMM submodule.
- PR 998 Add IO reader/writer modules to API docs, fix for missing cudf.Series docs
- PR 1017 concatenate along columns for Series and DataFrames
- PR 1002 Support indexing a dataframe with another boolean dataframe
- PR 1018 Better concatenation for Series and Dataframes
- PR 1036 Use Numpydoc style docstrings
- PR 1047 Adding gdf_dtype_extra_info to gdf_column_view_augmented
- PR 1054 Added default ctor to SerialTrieNode to overcome Thrust issue in CentOS7 + CUDA10
- PR 1024 CSV Reader: Add support for hexadecimal integers in integral-type columns
- PR 1033 Update `fillna()` to use libcudf function `gdf_replace_nulls`
- PR 1066 Added inplace assignment for columns and select_dtypes for dataframes
- PR 1026 CSV Reader: Change the meaning and type of the quoting parameter to match Pandas
- PR 1100 Adds `CUDF_EXPECTS` error-checking macro
- PR 1092 Fix select_dtype docstring
- PR 1111 Added cudf::table
- PR 1108 Sorting for datetime columns
- PR 1120 Return a `Series` (not a `Column`) from `Series.cat.set_categories()`
- PR 1128 CSV Reader: The last data row does not need to be line terminated
- PR 1183 Bump Arrow version to 0.12.1
- PR 1208 Default to CXX11_ABI=ON
- PR 1252 Fix NVStrings dependencies for cuda 9.2 and 10.0

Bug Fixes

- PR 821 Fix flake8 issues revealed by flake8 update
- PR 808 Resolved renamed `d_columns_valids` variable name
- PR 820 CSV Reader: fix the issue where reader adds additional rows when file uses \r\n as a line terminator
- PR 780 CSV Reader: Fix scientific notation parsing and null values for empty quotes
- PR 815 CSV Reader: Fix data parsing when tabs are present in the input CSV file
- PR 850 Fix bug where left joins where the left df has 0 rows causes a crash
- PR 861 Fix memory leak by preserving the boolean mask index
- PR 875 Handle unnamed indexes in to/from arrow functions
- PR 877 Fix ingest of 1 row arrow tables in from arrow function
- PR 876 Added missing `<type_traits>` include
- PR 889 Deleted test_rmm.py which has now moved to RMM repo
- PR 866 Merge v0.5.1 numpy ABI hotfix into 0.6
- PR 917 value_counts return int type on empty columns
- PR 611 Renamed `gdf_reduce_optimal_output_size()` -> `gdf_reduction_get_intermediate_output_size()`
- PR 923 fix index for negative slicing for cudf dataframe and series
- PR 927 CSV Reader: Fix category GDF_CATEGORY hashes not being computed properly
- PR 921 CSV Reader: Fix parsing errors with delim_whitespace, quotations in the header row, unnamed columns
- PR 933 Fix handling objects of all nulls in series creation
- PR 940 CSV Reader: Fix an issue where the last data row is missing when using byte_range
- PR 945 CSV Reader: Fix incorrect datetime64 when milliseconds or space separator are used
- PR 959 Groupby: Problem with column name lookup
- PR 950 Converting dataframe/recarry with non-contiguous arrays
- PR 963 CSV Reader: Fix another issue with missing data rows when using byte_range
- PR 999 Fix 0 sized kernel launches and empty sort_index exception
- PR 993 Fix dtype in selecting 0 rows from objects
- PR 1009 Fix performance regression in `to_pandas` method on DataFrame
- PR 1008 Remove custom dask communication approach
- PR 1001 CSV Reader: Fix a memory access error when reading a large (>2GB) file with date columns
- PR 1019 Binary Ops: Fix error when one input column has null mask but other doesn't
- PR 1014 CSV Reader: Fix false positives in bool value detection
- PR 1034 CSV Reader: Fix parsing floating point precision and leading zero exponents
- PR 1044 CSV Reader: Fix a segfault when byte range aligns with a page
- PR 1058 Added support for `DataFrame.loc[scalar]`
- PR 1060 Fix column creation with all valid nan values
- PR 1073 CSV Reader: Fix an issue where a column name includes the return character
- PR 1090 Updating Doxygen Comments
- PR 1080 Fix dtypes returned from loc / iloc because of lists
- PR 1102 CSV Reader: Minor fixes and memory usage improvements
- PR 1174: Fix release script typo
- PR 1137 Add prebuild script for CI
- PR 1118 Enhanced the `DataFrame.from_records()` feature
- PR 1129 Fix join performance with index parameter from using numpy array
- PR 1145 Issue with .agg call on multi-column dataframes
- PR 908 Some testing code cleanup
- PR 1167 Fix issue with null_count not being set after inplace fillna()
- PR 1184 Fix iloc performance regression
- PR 1185 Support left_on/right_on and also on=str in merge
- PR 1200 Fix allocating bitmasks with numba instead of rmm in allocate_mask function
- PR 1223 gpuCI: Fix label on rapidsai channel on gpu build scripts
- PR 1242 Add explicit Thrust exec policy to fix NVCATEGORY_TEST segfault on some platforms
- PR 1246 Fix categorical tests that failed due to bad implicit type conversion
- PR 1255 Fix overwriting conda package main label uploads
- PR 1259 Add dlpack includes to pip build

Bug Fixes

- PR 842 Avoid using numpy via cimport to prevent ABI issues in Cython compilation

New Features

- PR 722 Add bzip2 decompression support to `read_csv()`
- PR 693 add ZLIB-based GZIP/ZIP support to `read_csv_strings()`
- PR 411 added null support to gdf_order_by (new API) and cudf_table::sort
- PR 525 Added GitHub Issue templates for bugs, documentation, new features, and questions
- PR 501 CSV Reader: Add support for user-specified decimal point and thousands separator to read_csv_strings()
- PR 455 CSV Reader: Add support for user-specified decimal point and thousands separator to read_csv()
- PR 439 add `DataFrame.drop` method similar to pandas
- PR 356 add `DataFrame.transpose` method and `DataFrame.T` property similar to pandas
- PR 505 CSV Reader: Add support for user-specified boolean values
- PR 350 Implemented Series replace function
- PR 490 Added print_env.sh script to gather relevant environment details when reporting cuDF issues
- PR 474 add ZLIB-based GZIP/ZIP support to `read_csv()`
- PR 547 Added melt similar to `pandas.melt()`
- PR 491 Add CI test script to check for updates to CHANGELOG.md in PRs
- PR 550 Add CI test script to check for style issues in PRs
- PR 558 Add CI scripts for cpu-based conda and gpu-based test builds
- PR 524 Add Boolean Indexing
- PR 564 Update python `sort_values` method to use updated libcudf `gdf_order_by` API
- PR 509 CSV Reader: Input CSV file can now be passed in as a text or a binary buffer
- PR 607 Add `__iter__` and iteritems to DataFrame class
- PR 643 added a new api gdf_replace_nulls that allows a user to replace nulls in a column

Improvements

- PR 426 Removed sort-based groupby and refactored existing groupby APIs. Also improves C++/CUDA compile time.
- PR 461 Add `CUDF_HOME` variable in README.md to replace relative pathing.
- PR 472 RMM: Created centralized rmm::device_vector alias and rmm::exec_policy
- PR 500 Improved the concurrent hash map class to support partitioned (multi-pass) hash table building.
- PR 454 Improve CSV reader docs and examples
- PR 465 Added templated C++ API for RMM to avoid explicit cast to `void**`
- PR 513 `.gitignore` tweaks
- PR 521 Add `assert_eq` function for testing
- PR 502 Simplify Dockerfile for local dev, eliminate old conda/pip envs
- PR 549 Adds `-rdynamic` compiler flag to nvcc for Debug builds
- PR 472 RMM: Created centralized rmm::device_vector alias and rmm::exec_policy
- PR 577 Added external C++ API for scatter/gather functions
- PR 500 Improved the concurrent hash map class to support partitioned (multi-pass) hash table building
- PR 583 Updated `gdf_size_type` to `int`
- PR 500 Improved the concurrent hash map class to support partitioned (multi-pass) hash table building
- PR 617 Added .dockerignore file. Prevents adding stale cmake cache files to the docker container
- PR 658 Reduced `JOIN_TEST` time by isolating overflow test of hash table size computation
- PR 664 Added Debuging instructions to README
- PR 651 Remove noqa marks in `__init__.py` files
- PR 671 CSV Reader: uncompressed buffer input can be parsed without explicitly specifying compression as None
- PR 684 Make RMM a submodule
- PR 718 Ensure sum, product, min, max methods pandas compatibility on empty datasets
- PR 720 Refactored Index classes to make them more Pandas-like, added CategoricalIndex
- PR 749 Improve to_arrow and from_arrow Pandas compatibility
- PR 766 Remove TravisCI references, remove unused variables from CMake, fix ARROW_VERSION in Cmake
- PR 773 Add build-args back to Dockerfile and handle dependencies based on environment yml file
- PR 781 Move thirdparty submodules to root and symlink in /cpp
- PR 843 Fix broken cudf/python API examples, add new methods to the API index

Bug Fixes

- PR 569 CSV Reader: Fix days being off-by-one when parsing some dates
- PR 531 CSV Reader: Fix incorrect parsing of quoted numbers
- PR 465 Added templated C++ API for RMM to avoid explicit cast to `void**`
- PR 473 Added missing <random> include
- PR 478 CSV Reader: Add api support for auto column detection, header, mangle_dupe_cols, usecols
- PR 495 Updated README to correct where cffi pytest should be executed
- PR 501 Fix the intermittent segfault caused by the `thousands` and `compression` parameters in the csv reader
- PR 502 Simplify Dockerfile for local dev, eliminate old conda/pip envs
- PR 512 fix bug for `on` parameter in `DataFrame.merge` to allow for None or single column name
- PR 511 Updated python/cudf/bindings/join.pyx to fix cudf merge printing out dtypes
- PR 513 `.gitignore` tweaks
- PR 521 Add `assert_eq` function for testing
- PR 537 Fix CMAKE_CUDA_STANDARD_REQURIED typo in CMakeLists.txt
- PR 447 Fix silent failure in initializing DataFrame from generator
- PR 545 Temporarily disable csv reader thousands test to prevent segfault (test re-enabled in PR 501)
- PR 559 Fix Assertion error while using `applymap` to change the output dtype
- PR 575 Update `print_env.sh` script to better handle missing commands
- PR 612 Prevent an exception from occuring with true division on integer series.
- PR 630 Fix deprecation warning for `pd.core.common.is_categorical_dtype`
- PR 622 Fix Series.append() behaviour when appending values with different numeric dtype
- PR 603 Fix error while creating an empty column using None.
- PR 673 Fix array of strings not being caught in from_pandas
- PR 644 Fix return type and column support of dataframe.quantile()
- PR 634 Fix create `DataFrame.from_pandas()` with numeric column names
- PR 654 Add resolution check for GDF_TIMESTAMP in Join
- PR 648 Enforce one-to-one copy required when using `numba>=0.42.0`
- PR 645 Fix cmake build type handling not setting debug options when CMAKE_BUILD_TYPE=="Debug"
- PR 669 Fix GIL deadlock when launching multiple python threads that make Cython calls
- PR 665 Reworked the hash map to add a way to report the destination partition for a key
- PR 670 CMAKE: Fix env include path taking precedence over libcudf source headers
- PR 674 Check for gdf supported column types
- PR 677 Fix 'gdf_csv_test_Dates' gtest failure due to missing nrows parameter
- PR 604 Fix the parsing errors while reading a csv file using `sep` instead of `delimiter`.
- PR 686 Fix converting nulls to NaT values when converting Series to Pandas/Numpy
- PR 689 CSV Reader: Fix behavior with skiprows+header to match pandas implementation
- PR 691 Fixes Join on empty input DFs
- PR 706 CSV Reader: Fix broken dtype inference when whitespace is in data
- PR 717 CSV reader: fix behavior when parsing a csv file with no data rows
- PR 724 CSV Reader: fix build issue due to parameter type mismatch in a std::max call
- PR 734 Prevents reading undefined memory in gpu_expand_mask_bits numba kernel
- PR 747 CSV Reader: fix an issue where CUDA allocations fail with some large input files
- PR 750 Fix race condition for handling NVStrings in CMake
- PR 719 Fix merge column ordering
- PR 770 Fix issue where RMM submodule pointed to wrong branch and pin other to correct branches
- PR 778 Fix hard coded ABI off setting
- PR 784 Update RMM submodule commit-ish and pip paths
- PR 794 Update `rmm::exec_policy` usage to fix segmentation faults when used as temprory allocator.
- PR 800 Point git submodules to branches of forks instead of exact commits

New Features

- PR 398 add pandas-compatible `DataFrame.shape()` and `Series.shape()`
- PR 394 New documentation feature "10 Minutes to cuDF"
- PR 361 CSV Reader: Add support for strings with delimiters

Improvements

- PR 436 Improvements for type_dispatcher and wrapper structs
- PR 429 Add CHANGELOG.md (this file)
- PR 266 use faster CUDA-accelerated DataFrame column/Series concatenation.
- PR 379 new C++ `type_dispatcher` reduces code complexity in supporting many data types.
- PR 349 Improve performance for creating columns from memoryview objects
- PR 445 Update reductions to use type_dispatcher. Adds integer types support to sum_of_squares.
- PR 448 Improve installation instructions in README.md
- PR 456 Change default CMake build to Release, and added option for disabling compilation of tests

Bug Fixes

- PR 444 Fix csv_test CUDA too many resources requested fail.
- PR 396 added missing output buffer in validity tests for groupbys.
- PR 408 Dockerfile updates for source reorganization
- PR 437 Add cffi to Dockerfile conda env, fixes "cannot import name 'librmm'"
- PR 417 Fix `map_test` failure with CUDA 10
- PR 414 Fix CMake installation include file paths
- PR 418 Properly cast string dtypes to programmatic dtypes when instantiating columns
- PR 427 Fix and tests for Concatenation illegal memory access with nulls

New Features

- PR 336 CSV Reader string support

Improvements

- PR 354 source code refactored for better organization. CMake build system overhaul. Beginning of transition to Cython bindings.
- PR 290 Add support for typecasting to/from datetime dtype
- PR 323 Add handling pyarrow boolean arrays in input/out, add tests
- PR 325 GDF_VALIDITY_UNSUPPORTED now returned for algorithms that don't support non-empty valid bitmasks
- PR 381 Faster InputTooLarge Join test completes in ms rather than minutes.
- PR 373 .gitignore improvements
- PR 367 Doc cleanup & examples for DataFrame methods
- PR 333 Add Rapids Memory Manager documentation
- PR 321 Rapids Memory Manager adds file/line location logging and convenience macros
- PR 334 Implement DataFrame `__copy__` and `__deepcopy__`
- PR 271 Add NVTX ranges to pygdf
- PR 311 Document system requirements for conda install

Bug Fixes

- PR 337 Retain index on `scale()` function
- PR 344 Fix test failure due to PyArrow 0.11 Boolean handling
- PR 364 Remove noexcept from managed_allocator; CMakeLists fix for NVstrings
- PR 357 Fix bug that made all series be considered booleans for indexing
- PR 351 replace conda env configuration for developers
- PRs 346 360 Fix CSV reading of negative numbers
- PR 342 Fix CMake to use conda-installed nvstrings
- PR 341 Preserve categorical dtype after groupby aggregations
- PR 315 ReadTheDocs build update to fix missing libcuda.so
- PR 320 FIX out-of-bounds access error in reductions.cu
- PR 319 Fix out-of-bounds memory access in libcudf count_valid_bits
- PR 303 Fix printing empty dataframe