Unknown GhostScript error after successful camelot installation

Hello, I am currently on an Amazon EC2 Linux machine and have installed camelot through Anaconda with conda install -c conda-forge camelot-py. The installation happened without any issues. I could see Ghostscript as part of the dependencies being installed through Anaconda.

Afterwards, I attempted to extract the table from the example foo.pdf. From the documentation, this should be a simple tables = camelot.read_pdf('foo.pdf'). However, immediately after running that command, I received the following long error.

---------------------------------------------------------------------------
GhostscriptError                          Traceback (most recent call last)
<ipython-input-8-6d588ec94ca5> in <module>
----> 1 tables = camelot.read_pdf('./PDFs/foo.pdf')

/usr/local/.../lib/python3.8/site-packages/camelot/io.py in read_pdf(filepath, pages, password, flavor, suppress_stdout, layout_kwargs, **kwargs)
    111         p = PDFHandler(filepath, pages=pages, password=password)
    112         kwargs = remove_extra(kwargs, flavor=flavor)
--> 113         tables = p.parse(
    114             flavor=flavor,
    115             suppress_stdout=suppress_stdout,

/usr/local/.../lib/python3.8/site-packages/camelot/handlers.py in parse(self, flavor, suppress_stdout, layout_kwargs, **kwargs)
    169             parser = Lattice(**kwargs) if flavor == "lattice" else Stream(**kwargs)
    170             for p in pages:
--> 171                 t = parser.extract_tables(
    172                     p, suppress_stdout=suppress_stdout, layout_kwargs=layout_kwargs
    173                 )

/usr/local/.../lib/python3.8/site-packages/camelot/parsers/lattice.py in extract_tables(self, filename, suppress_stdout, layout_kwargs)
    400             return []
    401 
--> 402         self._generate_image()
    403         self._generate_table_bbox()
    404 

/usr/local/.../lib/python3.8/site-packages/camelot/parsers/lattice.py in _generate_image(self)
    217         gs_call = gs_call.encode().split()
    218         null = open(os.devnull, "wb")
--> 219         with Ghostscript(*gs_call, stdout=null) as gs:
    220             pass
    221         null.close()

/usr/local/.../lib/python3.8/site-packages/camelot/ext/ghostscript/__init__.py in Ghostscript(*args, **kwargs)
     88     if __instance__ is None:
     89         __instance__ = gs.new_instance()
---> 90     return __Ghostscript(
     91         __instance__,
     92         args,

/usr/local/.../lib/python3.8/site-packages/camelot/ext/ghostscript/__init__.py in __init__(self, instance, args, stdin, stdout, stderr)
     37         if stdin or stdout or stderr:
     38             self.set_stdio(stdin, stdout, stderr)
---> 39         rc = gs.init_with_args(instance, args)
     40         self._initialized = True
     41         if rc == gs.e_Quit:

/usr/local/.../lib/python3.8/site-packages/camelot/ext/ghostscript/_gsprint.py in init_with_args(instance, argv)
    172     rc = libgs.gsapi_init_with_args(instance, len(argv), c_argv)
    173     if rc not in (0, e_Quit, e_Info):
--> 174         raise GhostscriptError(rc)
    175     return rc
    176 

GhostscriptError: -770376232

That number at the end appears to be change every time I run the command. It stays in that general area of -700 million. The error was when I was in a Jupyter Notebook. Running this while on the pure command line simply prints out a Segmentation Fault. Downgrading the Python version from 3.8 to 3.6 did not fix the issue.

I tried to see if this was a GhostScript problem, but running

gs -sDEVICE=txtwrite -o extractedText.txt ./PDFs/foo.pdf

worked as intended and I could see the text document all nicely formatted. I am unsure as to what the problem could be at this point. Any help is appreciated.

Thanks!

[vinayak-mehta]

Meanwhile, can you try installing the latest version with pip install "camelot-py[base]==0.10.1" and then trying out the poppler image conversion backend? Here’s a snippet:

import camelot
tables = camelot.read_pdf("https://camelot-py.readthedocs.io/en/master/_static/pdf/foo.pdf", backend="poppler")
tables[0]
# <Table shape=(7, 7)>

More info in the docs here: https://camelot-py.readthedocs.io/en/master/user/advanced.html#use-alternate-image-conversion-backends

[vinayak-mehta]

Yep only the lattice flavor uses ghostscript. I’ll have to figure out a way to reproduce this issue.