在 Mac OS (Yosemite) 上使用 psycopg2 的问题

Question

Currently I am installing psycopg2 for work within eclipse with python.

I am finding a lot of problems:

1. The first problem sudo pip3.4 install psycopg2 is not working and it is showing the following message

Error: pg_config executable not found.

FIXED WITH: export PATH=/Library/PostgreSQL/9.4/bin/:"$PATH”

2. When I import psycopg2 in my project i obtein:

ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so Library libssl.1.0.0.dylib Library libcrypto.1.0.0.dylib

FIXED WITH: sudo ln -s /Library/PostgreSQL/9.4/lib/libssl.1.0.0.dylib /usr/lib sudo ln -s /Library/PostgreSQL/9.4/lib/libcrypto.1.0.0.dylib /usr/lib

3. Now I am obtaining:

ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so, 2): Symbol not found: _lo_lseek64 Referenced from: /Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so Expected in: /usr/lib/libpq.5.dylib in /Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so

Can you help me?

Answer 1

You need to replace the /usr/lib/libpq.5.dylib library because its version is too old.
Here's my solution to this problem:

$ sudo mv /usr/lib/libpq.5.dylib /usr/lib/libpq.5.dylib.old  
$ sudo ln -s /Library/PostgreSQL/9.4/lib/libpq.5.dylib /usr/lib

Answer 2

If you are using PostgresApp, you need to run the following two commands:

sudo mv /usr/lib/libpq.5.dylib /usr/lib/libpq.5.dylib.old
sudo ln -s /Applications/Postgres.app/Contents/Versions/9.4/lib/libpq.5.dylib /usr/lib

Answer 3

通过使用 psycopg2-binary 而不是 psycopg2，我能够在我的 Mac（运行 Catalina，10.15.3）上解决这个问题。

pip3 uninstall psycopg2 pip3 install psycopg2-binary

Answer 4

I am using yosemite, postgres.app & django. this got psycopg2 to load properly for me but the one difference was that my libpq.5.dylib file is in /Applications/Postgres.app/Contents/Versions/9.4/lib .

thus my second line was sudo ln -s /Applications/Postgres.app/Contents/Versions/9.4/lib/libpq.5.dylib /usr/lib

Answer 5

Here's a fix that worked for me on El Capitan that doesn't require restarting to work around the OS X El Capitan System Integrity Protection (SIP):

brew unlink postgresql && brew link postgresql
brew link --overwrite postgresql

H/T Farhan Ahmad

Answer 6

对于那些在 El Capitan 上无法使用 @KungFuLucky7 的答案的人 - 我使用以下方法来解决问题（在需要时调整路径以匹配您的路径）。

sudo install_name_tool -change libpq.5.dylib /Library/PostgreSQL/9.5/lib/libpq.5.dylib /usr/local/lib/python2.7/site-packages/psycopg2/_psycopg.so

Answer 7

In El Capitan, I used the same solution as @Forbze but 2 more commands as follows.

sudo install_name_tool -change libpq.5.dylib /Library/PostgreSQL/9.3/lib/libpq.5.dylib  /Library/Python/2.7/site-packages/psycopg2/_psycopg.so
sudo install_name_tool -change libssl.1.0.0.dylib /Library/PostgreSQL/9.3/lib/libssl.1.0.0.dylib  /Library/Python/2.7/site-packages/psycopg2/_psycopg.so
sudo install_name_tool -change libcrypto.1.0.0.dylib /Library/PostgreSQL/9.3/lib/libcrypto.1.0.0.dylib  /Library/Python/2.7/site-packages/psycopg2/_psycopg.so

It works perfectly!

Answer 8

well, I'd like to give my solution, the problem is related with the version of c. So, I just typed:

CFLAGS='-std=c99' pip install psycopg2==2.6.1