install pycurl with problems curl-config and ssl libs
In centos 7 and python 3.6 environment, install pycurl with pip3, may get the problems:
1)["Errno 2"] No such file or director:'curl-config'
2)__main__.ConfigurationError:Curl is configured to use SSL, but we have not been able to determine which SSL backend it is using.
Solutions for 'curl-config' Error
1) yum install libcurl-devel
Solutions for more SSL libs
export PYCURL_SSL_LIBRARY=openssl
export PYCURL_SSL_LIBRARY=nss
pip3 install pycurl
