pip安裝django-heroku報Error: pg_config executable not found.

 pip安裝django-heroku時出錯信息如下：

Collecting django-heroku==0.3.1
  Downloading https://mirrors.163.com/pypi/packages/59/af/5475a876c5addd5a3494db47d9f7be93cc14d3a7603542b194572791b6c6/django_heroku-0.3.1-py2.py3-none-any.whl
Collecting django (from django-heroku==0.3.1)
  Downloading https://mirrors.163.com/pypi/packages/9d/04/04abb097c84c770180eeebe7ed920ce42f9917ab5ad4de01ff8ed11bc25b/Django-3.0.6-py3-none-any.whl (7.5MB)
    100% |################################| 7.5MB 191kB/s 
Collecting whitenoise (from django-heroku==0.3.1)
  Downloading https://mirrors.163.com/pypi/packages/ae/25/0c8f08c9d3c93192cd286594f1e87b17bab496fb9082c2a69e17051b91fd/whitenoise-5.0.1-py2.py3-none-any.whl
Collecting psycopg2 (from django-heroku==0.3.1)
  Downloading https://mirrors.163.com/pypi/packages/a8/8f/1c5690eebf148d1d1554fc00ccf9101e134636553dbb75bdfef4f85d7647/psycopg2-2.8.5.tar.gz (380kB)
    100% |################################| 389kB 3.5MB/s 
    Complete output from command python setup.py egg_info:
    running egg_info
    creating pip-egg-info/psycopg2.egg-info
    writing pip-egg-info/psycopg2.egg-info/PKG-INFO
    writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
    writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
    writing manifest file 'pip-egg-info/psycopg2.egg-info/SOURCES.txt'
    
    Error: pg_config executable not found.
    
    pg_config is required to build psycopg2 from source.  Please add the directory
    containing pg_config to the $PATH or specify the full executable path with the
    option:
    
        python setup.py build_ext --pg-config /path/to/pg_config build ...
    
    or with the pg_config option in 'setup.cfg'.
    
    If you prefer to avoid building psycopg2 from source, please install the PyPI
    'psycopg2-binary' package instead.
    
    For further information please check the 'doc/src/install.rst' file (also at
    <https://www.psycopg.org/docs/install.html>).
    
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-n6fpjkgb/psycopg2/

這是由於安裝psycopg2出現了問題，可以安裝psycopg2-binary代替psycopg2

解決方法：

先安裝django-heroku的依賴：

pip install django 

pip install whitenoise

安裝psycopg2-binary：

pip install psycopg2-binary

最後無依賴安裝django-heroku

pip install --no-dependencies django-heroku