pip或easy_install安裝庫報錯：SSL: CERTIFICATE_VERIFY_FAILED

　　使用pip和easy_install安裝那個lxml、pyspider這些庫或者框架一直提示如下錯誤：

Collecting pyspider
  Could not fetch URL https://pypi.python.org/simple/pyspider/: There was a prob
lem confirming the ssl certificate: [SSL: CERTIFICATE_VERIFY_FAILED] certificate
 verify failed (_ssl.c:661) - skipping
  Could not find a version that satisfies the requirement pyspider (from version
s: )
No matching distribution found for pyspider

Searching for pyspider
Reading https://pypi.python.org/simple/pyspider/
Download error on https://pypi.python.org/simple/pyspider/: [SSL: CERTIFICATE_VE
RIFY_FAILED] certificate verify failed (_ssl.c:661) -- Some packages may not be
found!
Couldn't find index page for 'pyspider' (maybe misspelled?)
Scanning index of all packages (this may take a while)
Reading https://pypi.python.org/simple/
Download error on https://pypi.python.org/simple/: [SSL: CERTIFICATE_VERIFY_FAIL
ED] certificate verify failed (_ssl.c:661) -- Some packages may not be found!
No local packages or working download links found for pyspider
error: Could not find suitable distribution for Requirement.parse('pyspider')

　　錯誤緣由：SSL：CERTIFICATE_VERIFY_FAILED]證書驗證失敗（_ssl.c：661）

　　解決辦法：

# 1.pip install --index-url=http://pypi.python.org/simple/ --trusted-host pypi.python.org pythonPackageName
# 2.pip --trusted-host pypi.python.org install pythonPackageName

　　以上兩種命令都行，其中 "pythonPackageName" 是你要安裝的庫名稱（好比：requests、lxml等）