How to run a CLI command from a Python script?

Question

When I write this in CMD (Windows 10) it's OK. The recognized text is in the clipboard: "C: \\ Program Files (x86) \\ ABBYY FineReader 15 \\ FineReaderOcr.exe" "C: \\ Python39 \\ Scripts \\ abbyy \\ Skan.JPG" / send Clipboard

I would like to do the same with a Python script to be able to parse the contents of the clipboard. I am trying to do this using:

import sys
import os
def mycmd():
  os.system('cmd /c "C:\Program Files (x86)"\ABBYY FineReader 15\FineReaderOcr.exe" "skan.JPG" " /send Clipboard"')
mycmd()

But it doesn't work and you get the following error: 'C: \\ Program' is not recognized as an internal or external command, operable program or batch file.

I also tried using subprocess: import of os

import subprocess
program = 'C: \ Program Files (x86) \ ABBYY FineReader 15 \ FineReaderOcr.exe'
file = 'C: \ Python39 \ Scripts \ abbyy \ Skan.JPG'
lang = "/ lang Polish"
send = "/ send Clipboard"
subprocess.run (["C: \ Program Files (x86) \ ABBYY FineReader 15 \ FineReaderOcr.exe", "scan.JPG", "/ send Clipboard"])
subprocess.call ([program, file, send])

But it also doesn't work as it should. Please tell me why it doesn't work and how to do it correctly?

regards

Answer 1

Whitespace is important.

The space within Program Files is making that first file path be interpreted as two separate arguments, and it doesn't know how to interpret the first one, C:\\Program as a command.

I've made a few similar examples to illustrate what works and what doesn't:

File paths that use no spaces

>>> import os
>>> os.system('C:\ProgramData\Miniconda3\python.exe --version')
Python 3.9.1
0
>>> os.system('cmd /c "C:\ProgramData\Miniconda3\python.exe --version"')
Python 3.9.1
0
>>> os.system(r'cmd /c "C:\ProgramData\Miniconda3\python.exe --version"')
Python 3.9.1
0

These 3 versions are all successful because C:\\ProgramData\\Miniconda3\\python.exe , the file path in question, has no spaces in it.

File paths with spaces and \\u\u003c/i>

This command doesn't work:

>>> os.system('C:\Program Files (x86)\LilyPond\usr\bin\python.exe --version')
  File "<stdin>", line 1
    os.system('C:\Program Files (x86)\LilyPond\usr\bin\python.exe --version')
                                                                            ^
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 31-32: truncated \uXXXX escape

because it contains \\u\u003c/code> (in ...\\usr\\... ). When you use \\u\u003c/code> as part of a string, python expects it to be a part of a Unicode escape sequence (eg print("\’") will get you a special apostrophe)

The way to fix this is to either escape your backslashes with another backslash (eg 'C:\\\\ProgramData\\\\...' ) or by making it a "raw" string with a prefixed r : r'C:\\ProgramData\\...'

That gets us here:

>>> os.system(r'C:\Program Files (x86)\LilyPond\usr\bin\python.exe --version')
'C:\Program' is not recognized as an internal or external command,
operable program or batch file.
1

which is the problem I initially described; spaces are used to break up commands/arguments and cannot plainly be included in file paths.

The solution is to put quotes around the whole file path which contains a space:

>>> os.system(r'"C:\Program Files (x86)\LilyPond\usr\bin\python.exe" --version')
Python 3.7.4
0

These same things apply when the command is being sent as an argument:

>>> os.system(r'cmd /c "C:\Program Files (x86)\LilyPond\usr\bin\python.exe --version"')
'C:\Program' is not recognized as an internal or external command,
operable program or batch file.
1
>>> os.system(r'cmd /c ""C:\Program Files (x86)\LilyPond\usr\bin\python.exe" --version"')
Python 3.7.4
0

Conclusion

So it seems that your line should look something like this:

os.system(r'cmd /c ""C:\Program Files (x86)\ABBYY FineReader 15\FineReaderOcr.exe" skan.JPG" /send Clipboard')

(though I don't know what the /send Clipboard part is for, and so may need adjustment from this. However, this should address the error asked about in the question)