pip install -r requirements.txt -i http://pypi.douban.com/simple --trusted-host pypi.douban.com这一步报错，请大神指点下。
如下：
ERROR: Command errored out with exit status 1:
command: /usr/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/zn/0n3tgbd54r58lv4_bzl9rntw0000gn/T/pip-install-WXabU3/futu-api/setup.py'"'"'; file='"'"'/private/var/folders/zn/0n3tgbd54r58lv4_bzl9rntw0000gn/T/pip-install-WXabU3/futu-api/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(file);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, file, '"'"'exec'"'"'))' egg_info --egg-base /private/var/folders/zn/0n3tgbd54r58lv4_bzl9rntw0000gn/T/pip-pip-egg-info-l3Lixb
cwd: /private/var/folders/zn/0n3tgbd54r58lv4_bzl9rntw0000gn/T/pip-install-WXabU3/futu-api/
Complete output (5 lines):
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/private/var/folders/zn/0n3tgbd54r58lv4_bzl9rntw0000gn/T/pip-install-WXabU3/futu-api/setup.py", line 32, in <module>
with open("README.md", "r", encoding='utf-8') as fh:

TypeError: 'encoding' is an invalid keyword argument for this function
----------------------------------------

ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.