step1: Open Anaconda Prompt and activate the corresponding environment (that is, the environment where sklearn needs to be installed, or the environment of your current pycharm project, for example, I use "tf3" here);
step2：anaconda search -t conda sklearn;
step3:anaconda show gafortiby/sklearn-pandas；
Note: "gafortiby/sklearn-pandas" is selected according to your needs (system version: window, linux, osx; python version: py36, py37...)
step4:conda install --channel https://conda.anaconda.org/gafortiby sklearn-pandas (this command is the same as the last line in the picture above)
step4: Installation is successful, run the program.