[python] Drop Python 2 support (#3581)

* Update setup.py * Update .appveyor.yml * Update .travis.yml * Update .vsts-ci.yml * Update __init__.py * Update test.sh * Update test_windows.ps1 * Update advanced_example.py * Update requirements_base.txt * Update conf.py * Update conf.py * Update test_engine.py * Update utils.py * Update dockerfile-r * Update README.md * Update dockerfile.gpu * Update test_consistency.py * Update basic.py * Update compat.py * Update engine.py * Update sklearn.py * Update sklearn.py * Update callback.py * Update setup.py * Update __init__.py * Update plotting.py * Update sklearn.py * Update engine.py * Update compat.py * Update callback.py * Update basic.py * Update compat.py * Update basic.py * Update basic.py * Update compat.py * Update compat.py * Update plotting.py * Update engine.py * Update basic.py * Update sklearn.py * Update compat.py * Update engine.py * Update engine.py * Update callback.py * Update basic.py * Update basic.py * Update basic.py * Update basic.py * Update basic.py * Update sklearn.py * Update sklearn.py * Update plotting.py * Update sklearn.py * Update compat.py * Update compat.py * Update engine.py * Update plotting.py * Update sklearn.py * Update basic.py * Update basic.py * Update basic.py * Update basic.py * Update compat.py * Update compat.py * Update compat.py * Update engine.py * Update basic.py * Update compat.py * Update basic.py * Update basic.py * Update basic.py * Update compat.py * Update compat.py * Update basic.py * Update basic.py * Update .vsts-ci.yml * Update .vsts-ci.yml * Update conf.py * Revert "Update dockerfile-r" This reverts commit 4ff6ffc.
microsoft · Dec 9, 2020 · 44a6fb7 · 44a6fb7
1 parent 1fb82e2
commit 44a6fb7
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Showing 21 changed files with 147 additions and 272 deletions.
diff --git a/.appveyor.yml b/.appveyor.yml
@@ -28,7 +28,6 @@ install:
   - set CONDA_ENV="test-env"
   - ps: >-
       switch ($env:PYTHON_VERSION) {
-          "2.7" {$env:MINICONDA = "C:\Miniconda-x64"}
           "3.6" {$env:MINICONDA = "C:\Miniconda36-x64"}
           "3.7" {$env:MINICONDA = "C:\Miniconda37-x64"}
           default {$env:MINICONDA = "C:\Miniconda37-x64"}

diff --git a/.ci/test.sh b/.ci/test.sh
@@ -100,15 +100,15 @@ if [[ $TASK == "sdist" ]]; then
     exit 0
 elif [[ $TASK == "bdist" ]]; then
     if [[ $OS_NAME == "macos" ]]; then
-        cd $BUILD_DIRECTORY/python-package && python setup.py bdist_wheel --plat-name=macosx --universal || exit -1
-        mv dist/lightgbm-$LGB_VER-py2.py3-none-macosx.whl dist/lightgbm-$LGB_VER-py2.py3-none-macosx_10_13_x86_64.macosx_10_14_x86_64.macosx_10_15_x86_64.whl
+        cd $BUILD_DIRECTORY/python-package && python setup.py bdist_wheel --plat-name=macosx --python-tag py3 || exit -1
+        mv dist/lightgbm-$LGB_VER-py3-none-macosx.whl dist/lightgbm-$LGB_VER-py3-none-macosx_10_13_x86_64.macosx_10_14_x86_64.macosx_10_15_x86_64.whl
         if [[ $AZURE == "true" ]]; then
-            cp dist/lightgbm-$LGB_VER-py2.py3-none-macosx*.whl $BUILD_ARTIFACTSTAGINGDIRECTORY
+            cp dist/lightgbm-$LGB_VER-py3-none-macosx*.whl $BUILD_ARTIFACTSTAGINGDIRECTORY
         fi
     else
-        cd $BUILD_DIRECTORY/python-package && python setup.py bdist_wheel --plat-name=manylinux1_x86_64 --universal || exit -1
+        cd $BUILD_DIRECTORY/python-package && python setup.py bdist_wheel --plat-name=manylinux1_x86_64 --python-tag py3 || exit -1
         if [[ $AZURE == "true" ]]; then
-            cp dist/lightgbm-$LGB_VER-py2.py3-none-manylinux1_x86_64.whl $BUILD_ARTIFACTSTAGINGDIRECTORY
+            cp dist/lightgbm-$LGB_VER-py3-none-manylinux1_x86_64.whl $BUILD_ARTIFACTSTAGINGDIRECTORY
         fi
     fi
     pip install --user $BUILD_DIRECTORY/python-package/dist/*.whl || exit -1

diff --git a/.ci/test_windows.ps1 b/.ci/test_windows.ps1
@@ -49,7 +49,7 @@ elseif ($env:TASK -eq "sdist") {
 }
 elseif ($env:TASK -eq "bdist") {
   cd $env:BUILD_SOURCESDIRECTORY/python-package
-  python setup.py bdist_wheel --plat-name=win-amd64 --universal ; Check-Output $?
+  python setup.py bdist_wheel --plat-name=win-amd64 --python-tag py3 ; Check-Output $?
   cd dist; pip install @(Get-ChildItem *.whl) ; Check-Output $?
   cp @(Get-ChildItem *.whl) $env:BUILD_ARTIFACTSTAGINGDIRECTORY
 } elseif (($env:APPVEYOR -eq "true") -and ($env:TASK -eq "python")) {

diff --git a/.travis.yml b/.travis.yml
@@ -17,7 +17,7 @@ env:
     - PYTHON_VERSION=3.8
   matrix:
     - TASK=regular PYTHON_VERSION=3.6
-    - TASK=sdist PYTHON_VERSION=2.7
+    - TASK=sdist
     - TASK=bdist
     - TASK=if-else
     - TASK=lint

diff --git a/.vsts-ci.yml b/.vsts-ci.yml
@@ -117,7 +117,6 @@ jobs:
         PYTHON_VERSION: 3.6
       sdist:
         TASK: sdist
-        PYTHON_VERSION: 2.7
       bdist:
         TASK: bdist
   steps:

diff --git a/docker/gpu/README.md b/docker/gpu/README.md
@@ -13,13 +13,12 @@
 # Dockerfile for LightGBM GPU Version with Python
 
 `dockerfile.gpu` - A docker file with LightGBM utilizing nvidia-docker. The file is based on the `nvidia/cuda:8.0-cudnn5-devel` image.
-LightGBM can be utilized in GPU and CPU modes and via Python (2.7 & 3.6).
+LightGBM can be utilized in GPU and CPU modes and via Python.
 
 ## Contents
 
 - LightGBM (cpu + gpu)
-- Python 2.7 (conda) + scikit-learn, notebooks, pandas, matplotlib
-- Python 3.6 (conda) + scikit-learn, notebooks, pandas, matplotlib
+- Python 3.8 (conda) + scikit-learn, notebooks, pandas, matplotlib
 
 Running the container starts a Jupyter Notebook at `localhost:8888`.
 

diff --git a/docker/gpu/dockerfile.gpu b/docker/gpu/dockerfile.gpu
@@ -75,8 +75,7 @@ RUN echo "export PATH=$CONDA_DIR/bin:"'$PATH' > /etc/profile.d/conda.sh && \
     rm ~/miniconda.sh
 
 RUN conda config --set always_yes yes --set changeps1 no && \
-    conda create -y -q -n py2 python=2.7 mkl numpy scipy scikit-learn jupyter notebook ipython pandas matplotlib && \
-    conda create -y -q -n py3 python=3.6 mkl numpy scipy scikit-learn jupyter notebook ipython pandas matplotlib
+    conda create -y -q -n py3 python=3.8 mkl numpy scipy scikit-learn jupyter notebook ipython pandas matplotlib
 
 #################################################################################################################
 #           LightGBM
@@ -90,7 +89,6 @@ RUN cd /usr/local/src && mkdir lightgbm && cd lightgbm && \
 
 ENV PATH /usr/local/src/lightgbm/LightGBM:${PATH}
 
-RUN /bin/bash -c "source activate py2 && cd /usr/local/src/lightgbm/LightGBM/python-package && python setup.py install --precompile && source deactivate"
 RUN /bin/bash -c "source activate py3 && cd /usr/local/src/lightgbm/LightGBM/python-package && python setup.py install --precompile && source deactivate"
 
 #################################################################################################################

diff --git a/docs/conf.py b/docs/conf.py
@@ -26,17 +26,13 @@
 from docutils.parsers.rst import Directive
 from sphinx.errors import VersionRequirementError
 from subprocess import PIPE, Popen
+from unittest.mock import Mock
 
 CURR_PATH = os.path.abspath(os.path.dirname(__file__))
 LIB_PATH = os.path.join(CURR_PATH, os.path.pardir, 'python-package')
 sys.path.insert(0, LIB_PATH)
 
 # -- mock out modules
-try:
-    from unittest.mock import Mock  # Python 3.x
-except ImportError:
-    from mock import Mock  # Python 2.x
-
 MOCK_MODULES = ['numpy', 'scipy', 'scipy.sparse',
                 'sklearn', 'matplotlib', 'pandas', 'graphviz']
 for mod_name in MOCK_MODULES:
@@ -208,9 +204,7 @@ def generate_doxygen_xml(app):
         "WARN_AS_ERROR=YES",
     ]
     doxygen_input = '\n'.join(doxygen_args)
-    is_py3 = sys.version[0] == "3"
-    if is_py3:
-        doxygen_input = bytes(doxygen_input, "utf-8")
+    doxygen_input = bytes(doxygen_input, "utf-8")
     if not os.path.exists(os.path.join(CURR_PATH, 'doxyoutput')):
         os.makedirs(os.path.join(CURR_PATH, 'doxyoutput'))
     try:
@@ -221,8 +215,7 @@ def generate_doxygen_xml(app):
         process = Popen(["doxygen", "-"],
                         stdin=PIPE, stdout=PIPE, stderr=PIPE)
         stdout, stderr = process.communicate(doxygen_input)
-        output = '\n'.join([i.decode('utf-8') if is_py3 else i
-                            for i in (stdout, stderr) if i is not None])
+        output = '\n'.join([i.decode('utf-8') for i in (stdout, stderr) if i is not None])
         if process.returncode != 0:
             raise RuntimeError(output)
         else:

diff --git a/docs/requirements_base.txt b/docs/requirements_base.txt
@@ -1,3 +1,2 @@
 sphinx
 sphinx_rtd_theme >= 0.3
-mock; python_version < '3'
diff --git a/examples/python-guide/advanced_example.py b/examples/python-guide/advanced_example.py
@@ -1,14 +1,11 @@
 # coding: utf-8
 import json
+import pickle
 import lightgbm as lgb
 import pandas as pd
 import numpy as np
 from sklearn.metrics import mean_squared_error
 
-try:
-    import cPickle as pickle
-except BaseException:
-    import pickle
 
 print('Loading data...')
 # load or create your dataset

diff --git a/python-package/lightgbm/__init__.py b/python-package/lightgbm/__init__.py
@@ -3,16 +3,12 @@
 
 Contributors: https://github.com/microsoft/LightGBM/graphs/contributors.
 """
-from __future__ import absolute_import
-
 from .basic import Booster, Dataset
 from .callback import (early_stopping, print_evaluation, record_evaluation,
                        reset_parameter)
 from .engine import cv, train, CVBooster
 
 import os
-import sys
-import warnings
 
 try:
     from .sklearn import LGBMModel, LGBMRegressor, LGBMClassifier, LGBMRanker
@@ -36,8 +32,3 @@
            'LGBMModel', 'LGBMRegressor', 'LGBMClassifier', 'LGBMRanker',
            'print_evaluation', 'record_evaluation', 'reset_parameter', 'early_stopping',
            'plot_importance', 'plot_split_value_histogram', 'plot_metric', 'plot_tree', 'create_tree_digraph']
-
-# REMOVEME: remove warning after 3.1.0 version release
-if sys.version_info[0] == 2:
-    warnings.warn("LightGBM 3.1 version is the last version that supports Python 2.\n"
-                  "Next release will drop the support.", UserWarning)