[FLINK-19450][python][tests] Optimize the Python CI Test to reduce ex…

…ecution time

This closes apache#13520.

flink-python/dev/lint-python.sh

@@ -219,7 +219,11 @@ function install_miniconda() {
 
 # Install some kinds of py env.
 function install_py_env() {
- py_env=("3.5" "3.6" "3.7" "3.8")
+ if [[ ${BUILD_REASON} = 'IndividualCI' ]]; then
+ py_env=("3.8")
+ else
+ py_env=("3.5" "3.6" "3.7" "3.8")
+ fi
  for ((i=0;i<${#py_env[@]};i++)) do
  if [ -d "$CURRENT_DIR/.conda/envs/${py_env[i]}" ]; then
  rm -rf "$CURRENT_DIR/.conda/envs/${py_env[i]}"
@@ -529,14 +533,20 @@ function check_stage() {
 #########################
 # Tox check
 function tox_check() {
+ LATEST_PYTHON="py38"
  print_function "STAGE" "tox checks"
  # Set created py-env in $PATH for tox's creating virtual env
  activate
  # Ensure the permission of the scripts set correctly
  chmod +x $FLINK_PYTHON_DIR/../build-target/bin/*
  chmod +x $FLINK_PYTHON_DIR/dev/*
 
- $TOX_PATH -c $FLINK_PYTHON_DIR/tox.ini --recreate 2>&1 | tee -a $LOG_FILE
+ if [[ ${BUILD_REASON} = 'IndividualCI' ]]; then
+ # Only run test in latest python version triggered by a Git push
+ $TOX_PATH -c $FLINK_PYTHON_DIR/tox.ini -e ${LATEST_PYTHON} --recreate 2>&1 | tee -a $LOG_FILE
+ else
+ $TOX_PATH -c $FLINK_PYTHON_DIR/tox.ini --recreate 2>&1 | tee -a $LOG_FILE
+ fi
 
  TOX_RESULT=$((grep -c "congratulations :)" "$LOG_FILE") 2>&1)
  if [ $TOX_RESULT -eq '0' ]; then