pipenv换镜像源

换阿里云镜像：

python -c "s='https://mirrors.aliyun.com/pypi/simple';fn='Pipfile';pat=r'(\[\[source\]\]\s*url\s*=\s*\")(.+?)(\")';import re;fp=open(fn, 'r+');ss=fp.read();fp.seek(0);fp.truncate();fp.write(re.sub(pat, r'\1{}\3'.format(s), ss));fp.close();print('Done! Pipfile source switch to:\n'+s)"