我无法安装 pygresql。当我运行 pip install 时，我得到了这个：
(postgresql) Matts-MacBook-Pro:~ mattspeck$ pip install pygresql
Collecting pygresql
Using cached PyGreSQL-5.0.4.tar.gz
Complete output from command python setup.py egg_info:
sh: pg_config: command not found
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/private/var/folders/0q/fzk2q0_94tn_z1vlf446_jdr0000gn/T/pip-build-qOeMG3/pygresql/setup.py", line 88, in <module>
pg_version = pg_version()
File "/private/var/folders/0q/fzk2q0_94tn_z1vlf446_jdr0000gn/T/pip-build-qOeMG3/pygresql/setup.py", line 82, in pg_version
match = re.search(r'(\d+)\.(\d+)', pg_config('version'))
File "/private/var/folders/0q/fzk2q0_94tn_z1vlf446_jdr0000gn/T/pip-build-qOeMG3/pygresql/setup.py", line 74, in pg_config
raise Exception("pg_config tool is not available.")
Exception: pg_config tool is not available.
----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/0q/fzk2q0_94tn_z1vlf446_jdr0000gn/T/pip-build-qOeMG3/pygresql/
我在我的电脑上运行 Anaconda Python 2.7.13。
我已经尝试在 virtualenv 内外安装。任何人都知道为什么会发生这种情况/是否有修复？