Python安装setuptools遇到的MARKER_EXPR错误

# python setup.py install
Traceback (most recent call last):
  File "setup.py", line 11, in
    import setuptools
  File "/home/zhangsan/setuptools-34.4.1/setuptools/__init__.py", line 12, in
    import setuptools.version
  File "/home/zhangsan/setuptools-34.4.1/setuptools/version.py", line 1, in
    import pkg_resources
  File "/home/zhangsan/setuptools-34.4.1/pkg_resources/__init__.py", line 72, in
    import packaging.requirements
  File "/usr/local/lib/python2.7/site-packages/packaging/requirements.py", line 59, in
    MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
TypeError: __call__() takes exactly 2 arguments (1 given)


对于这个错误，只需要提示找到requirements.py的59行，将
MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
改成：
MARKER_EXPR = originalTextFor(MARKER_EXPR)("marker")
即可。

如果在安装psycopg2遇到错误：
Error: pg_config executable not found.

则表示需要安装包postgresql-devel：
yum install postgresql-devel