python ghostscript: RuntimeError: Can not find Ghostscript library (libgs)

Question

When trying to run hello-world example

import sys
import ghostscript

args = [
    "ps2pdf", # actual value doesn't matter
    "-dNOPAUSE", "-dBATCH", "-dSAFER",
    "-sDEVICE=pdfwrite",
    "-sOutputFile=" + sys.argv[1],
    "-c", ".setpdfwrite",
    "-f",  sys.argv[2]
    ]

ghostscript.Ghostscript(*args)

getting error:

 File "/Users/ddd/sss/ddd/eee.py", line 2, in <module>
    import ghostscript
  File "build/bdist.macosx-10.6-universal/egg/ghostscript/__init__.py", line 33, in <module>

  File "build/bdist.macosx-10.6-universal/egg/ghostscript/_gsprint.py", line 290, in <module>
RuntimeError: Can not find Ghostscript library (libgs)

what is this libgs library and how can I get it?

btw I'm on mac

Answer 1

For newer user who are using M1 mac, ghostscript might show a missing libgs file error and the file would be unavailable at usr/local/lib

The issue can be resolved by following these steps, in the same order:

• brew install ghostscript
• conda install ghostscript, which installs the arm_64 based library from conda-forge
• If conda throws a channel error try using conda install -c conda-forge ghostscript
• pip install ghostscript

Note:

1. The libgs.dylib file can be found in the home brew installation of ghostscript
2. Changing the address in _gsprint.py will throw an error as the brew installed version will be arm_64 based and the pip installed version will be OS_X86 based
3. Python doesn't recognise ghostscript module from conda install unless pip install is run, so that is an essential step

Answer 2

Ok, if you're on mac M1 and using python 3.9 that trick from the mentioned Github issue won't work probably. I did a few times what @Prajual suggested but didn't work either. This helps.

1. First,

brew install ghostscript

2. Check out in brew lib what your version is. there should be a directory named like 9.56.1_1

ls /opt/homebrew/Cellar/ghostscript/

3. Then copy that dylib file to where pip can access at /usr/local/lib/ -- needs sudo privilege. x.xx.xx would be your version from last command!

sudo cp /opt/homebrew/Cellar/ghostscript/x.xx.xx/lib/libgs.dylib /usr/local/lib/

You should now be able to import ghostscript with no problem.