错误：找不到 pg_config 可执行文件我尝试使用 python3.7 pip3 psycopg2

Question

我使用 aws linux ，默认 python 是 2.7 我yum安装了3.7 并更改了别名 python=python3 现在当我做 python -V 我得到：Python 3.7.6。 我运行 pip3 install psycopg2

得到：

pip3 install psycopg2
Defaulting to user installation because normal site-packages is not writeable
Collecting psycopg2
  Using cached psycopg2-2.8.5.tar.gz (380 kB)
    ERROR: Command errored out with exit status 1:
     command: /bin/python3 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-b3bpay2i/psycopg2/setup.py'"'"'; __file__='"'"'/tmp/pip-install-b3bpay2i/psycopg2/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-3c18jwyz
         cwd: /tmp/pip-install-b3bpay2i/psycopg2/
    Complete output (23 lines):
    running egg_info
    creating /tmp/pip-pip-egg-info-3c18jwyz/psycopg2.egg-info
    writing /tmp/pip-pip-egg-info-3c18jwyz/psycopg2.egg-info/PKG-INFO
    writing dependency_links to /tmp/pip-pip-egg-info-3c18jwyz/psycopg2.egg-info/dependency_links.txt
    writing top-level names to /tmp/pip-pip-egg-info-3c18jwyz/psycopg2.egg-info/top_level.txt
    writing manifest file '/tmp/pip-pip-egg-info-3c18jwyz/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>).

    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

我尝试 pip3 二进制文件 与：pip3 install psycopg2-binary 并做到了： pip3-列表 结果是：

Package         Version Location                                          Installer
--------------- ------- ------------------------------------------------- ---------
pip             20.1    /usr/local/lib/python3.7/site-packages            pip
psycopg2-binary 2.8.5   /home/ec2-user/.local/lib/python3.7/site-packages pip
setuptools      38.4.0  /usr/lib/python3.7/site-packages                  pip
wheel           0.34.2  /home/ec2-user/.local/lib/python3.7/site-packages pip

当我检查文件是否存在时：

ls -l /home/ec2-user/.local/lib/python3.7/site-packages
total 4
drwxrwxr-x 3 ec2-user ec2-user  302 Apr 30 15:06 psycopg2
drwxrwxr-x 2 ec2-user ec2-user  102 Apr 30 15:06 psycopg2_binary-2.8.5.dist-info
drwxrwxr-x 2 ec2-user ec2-user 4096 Apr 30 15:06 psycopg2_binary.libs
drwxrwxr-x 4 ec2-user ec2-user  233 Apr 30 16:03 wheel
drwxrwxr-x 2 ec2-user ec2-user  130 Apr 30 16:03 wheel-0.34.2.dist-info

还使用安装了 postgresql10 客户端

sudo amazon-linux-extras install postgresql10

为什么我仍然收到错误？

Answer 1

psycopg2-binary 包旨在让初学者无需满足构建要求即可开始使用Python 和PostgreSQL。 对于生产用途，建议您使用源代码分发版。。

因为连接 Postgre 数据库需要这个包，所以你需要libpq。 psycopg2 库是作为 libpq 的包装器构建的。它需要为 PostgreSQL 构建第 3 方应用程序所需的一些 PostgreSQL 二进制文件和头文件。运行：

$ sudo apt install python3-dev libpq-dev

上述命令的主要目标是提供构建psycopg2 的所有要求。要在您的系统中安装最新的软件包，请使用pip：

$ pip3 install psycopg2

如果您找不到pg_config，请检查您的路径。它可能不在您的 PATH 中。

在alpine 上，包含pg_config 的库是postgresql-dev。要安装，请运行：

apk update && \
 apk add postgresql-dev gcc python3-dev musl-dev

# Then you can install pyscopg2 say from your requirements.txt file or manually