In my program I call the command:
command_two = 'sfit4Layer0.py -bv5 -fs'
subprocess.call(command_two.split(), shell=False)
I am using PyCharm and I get the error message:
Traceback (most recent call last):
File "part2test.py", line 5, in <module>
subprocess.call(command_two.split(), shell=False) #writes the summary file
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 522, in call
return Popen(*popenargs, **kwargs).wait()
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 710, in __init__
errread, errwrite)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1335, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
When walking through my program, it never gets to the program I want it to sfit4Layer0.py, it is getting stuck in subprocess but I am not sure why. Changing the shell=True doesn't do anything helpful either - I don't get these error messages but it does not execute my code properly. Any suggestions would be helpful.
My bash profile:
PATH="~/bin:/usr/bin:${PATH}"
export PATH PYTHONPATH="/Users/nataliekille/Documents/sfit4/pbin/Layer0:/Users/nataliekille/Documents/sfit4/pbin/Layer1:/Users/nataliekille/Documents/sfit4/pbin/ModLib:/Users/nataliekille/Documents/sfit4/SpectralDB"
export PYTHONPATH
PATH=${PATH}:${PYTHONPATH}
export PATH
You've missed an important part of the subprocess documentation. "If passing a single string [at the command, rather than a list of strings], either shell must be True (see below) or else the string must simply name the program to be executed without specifying any arguments."
So the kernel is compaining because there is not executable with the name 'sfit4Layer0.py -bv5 -fs'. Should work if you replace the string with (for example) 'sfit4Layer0.py -bv5 -fs'.split(), or ['sfit4Layer0.py', '-bv5', '-fs'].
Related
I'm using a python script which uses subprocess to pass a commmand to the terminal. Part of the command that I'm passing involves paths which contain parentheses. Python handles strings with parentheses fine, but of course terminal does not handle these without escape characters.
I'm trying to pass variables to a command line program by feeding a string into subprocess, but here's simple example to reproduce the error:
import subprocess
path = '/home/user/Desktop/directory(2018)'
command_str = 'rmdir ' + path
print (subprocess.run(command_str))
which gives me this error:
Traceback (most recent call last):
File "ex.py", line 7, in <module>
print (subprocess.run(command_str))
File "/usr/lib/python3.6/subprocess.py", line 403, in run
with Popen(*popenargs, **kwargs) as process:
File "/usr/lib/python3.6/subprocess.py", line 709, in __init__
restore_signals, start_new_session)
File "/usr/lib/python3.6/subprocess.py", line 1344, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'rmdir /home/user/Desktop/directory(2018)': 'rmdir /home/user/Desktop/directory(2018)'
When I write it directly into the terminal with escape characters it works great.
$ rmdir /home/user/Desktop/directory\(2018\)
But in Python when I try to add escape characters to the strings before calling subprocess:
command_str = command_str.replace('(','\(')
command_str = command_str.replace(')','\)')
I get the same error as before because, unlike print, the subprocess string adds a second escape character which gets passed to the terminal.
Traceback (most recent call last):
File "ex.py", line 7, in <module>
print (subprocess.run(command_str))
File "/usr/lib/python3.6/subprocess.py", line 403, in run
with Popen(*popenargs, **kwargs) as process:
File "/usr/lib/python3.6/subprocess.py", line 709, in __init__
restore_signals, start_new_session)
File "/usr/lib/python3.6/subprocess.py", line 1344, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'rmdir /home/user/Desktop/directory\\(2018\\)': 'rmdir /home/user/Desktop/directory\\(2018\\)'
Is there a way to fix this particular error? Either by doing something different with replace or subprocess.run? (I'm not looking for a better way to remove directories.) Thanks.
Python implements rm and rmdir so no need to call a process. In general, if you want to skip shell processing on a command in subprocess, don't use the shell.
import subprocess
path = '/home/user/Desktop/directory(2018)'
command = ['rmdir', path]
print (subprocess.run(command, shell=False))
The shell breaks a command line into a list of arguments. You can build that list yourself and skip the shell completely.
Do not use subprocess, and you don't have to worry about shell escaping. Use the high-level file operation APIs provided in stdlib's shutil:
import shutil
shutil.rmtree('/home/user/Desktop/directory(2018)')
I'd like to use SVOX/pico2wave to write a wav-file from Python code. When I execute this line from a terminal the file is written just fine:
/usr/bin/pico2wave -w=/tmp/tmp_say.wav "Hello world."
I've verified that pico2wave is located in /usr/bin.
This is my Python code:
from subprocess import call
call('/usr/bin/pico2wave -w=/tmp/tmp_say.wav "Hello world."')
... which throws this error:
Traceback (most recent call last):
File "app/app.py", line 63, in <module>
call('/usr/bin/pico2wave -w=/tmp/tmp_say.wav "Hello world."')
File "/usr/lib/python2.7/subprocess.py", line 168, in call
return Popen(*popenargs, **kwargs).wait()
File "/usr/lib/python2.7/subprocess.py", line 390, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1024, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
From the documentation
Providing a sequence of arguments is generally preferred, as it allows
the module to take care of any required escaping and quoting of
arguments (e.g. to permit spaces in file names). If passing a single
string, either shell must be True (see below) or else the string must
simply name the program to be executed without specifying any
arguments.
So you might try with
call(['/usr/bin/pico2wave', '-w=/tmp/tmp_say.wav', '"Hello world."'])
So, I made a command called jel, which is executable as jel. It is run in Python, and when I run jel doctor, in jel.py it gives me a error(the main file). The code looks like this: Note that all necessary modules are already imported.
elif arg == 'doctor':
subprocess.call(['cd', 'js'])
ver = subprocess.call(['node', 'version.js'])
subprocess.call(['cd', '..'])
if not ver == version:
print 'jel doctor: \033[91found that version\033[0m ' + str(version) + ' \033[91mis not the current version\033[0m'
print 'jel doctor: \033[92mrun jel update\033[0m'
sys.exit()
The js file version.js is run on node, and looks like this: All necessary packages are installed
var latest = require('latest');
latest('jel', function(err, v) {
console.log(v);
// => "0.0.3"
if (err) {
console.log('An error occurred.');
}
});
It is giving me this error when the jel.py file uses subprocess to call cs js and node version.js:
Traceback (most recent call last):
File "/bin/jel", line 90, in <module>
subprocess.call(['cd', 'js'])
File "/usr/lib/python2.7/subprocess.py", line 522, in call
return Popen(*popenargs, **kwargs).wait()
File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
bjskistad:~/workspace (master) $ jel doctor
Traceback (most recent call last):
File "/bin/jel", line 90, in <module>
subprocess.call(['cd', 'js'])
File "/usr/lib/python2.7/subprocess.py", line 522, in call
return Popen(*popenargs, **kwargs).wait()
File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
I believe it is saying the directory doesn't exist, although it does. Do I need to call something else before?
There are at least three problems with your code snippet:
cd is a shell built-in, not an executable program. If you want to invoke cd, you'll need to invoke the shell.
The cd command only affects the shell in which it runs. It will have no effect upon the python program, or any subsequent subprocesses.
The return code from subprocess.call() is not the text that the program wrote to stdout. To get that text, try subprocess.check_output().
Try this:
#UNTESTED
elif arg == 'doctor':
ver = subprocess.check_output(['cd js && node version.js'], shell=True)
if not ver == version:
As already pointed out changing the directory is only reflected in the subprocess. You should use os.chdir to change your working directory but another alternative is to specify the cwd to subprocess which avoids any need to cd or os.chdir:
version = subprocess.check_output(['node', 'version.js'], cwd="js")
You should also use != in your if and you probably want to rstrip the newline:
if version != ver.rstrip():
When I try to shell out of my Python 3.51 program to run the Popen command I get the following errors. Yet when I copy the exact string I'm passing to Popen to the Terminal command line it works fine and opens the file in Adobe Reader which is my default app for the .pdf files.
Here is the Code:
finalCall = r'open /Users/gbarnabic/Documents/1111/combined.pdf'
print(finalCall)
pid_id = subprocess.Popen(finalCall).pid
Here is the error:
open /Users/gbarnabic/Documents/1111/combined.pdf
Exception in Tkinter callback
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/tkinter/init.py", line 1549, in call
return self.func(*args)
File "pdfcomb2.py", line 212, in change_dir
self.openPDF(outFileName, pageNum)
File "pdfcomb2.py", line 426, in openPDF
subprocess.run(finalCall)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 696, in run
with Popen(*popenargs, **kwargs) as process:
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 950, in init
restore_signals, start_new_session)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 1544, in _execute_child
raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'open /Users/gb/Documents/1111/combined.pdf'
Georges-MBP:filepicktest gb$ open /Users/gb/Documents/1111/combined.pdf
Georges-MBP:filepicktest gb$
With Popen you need to set shell=True to pass command as a string or split command in a list of arguments. Could be done with shlex
import shlex
import subprocess
subprocess.Popen(shlex.split('open ....'))
You could check example in documentation:
https://docs.python.org/2/library/subprocess.html#subprocess.Popen
So the error here means that Python try to run file with name open /Users/gb/Documents/1111/combined.pdf. Obviously it doesn't exist
I am using the subprocess module to run a command in python. But the problem is that I also want to include a string (for a file name) in the command.
An example of what I want to do:
from subprocess import call
command = "cd/DirectoryName"
call = [(command)]
In this specific example I want DirectoryName to be a variable determined by the user.
What I have tried to no avail:
Desktop=raw_input()
cmd="'cd %s'(Desktop/)"
call([cmd])
Here's the error I get when I try to run these commands in the python shell.
Chicken='Chicken'
command = 'say %s' % (Chicken)
print command
say Chicken
call([command])
Traceback (most recent call last):
File "/Applications/WingIDE.app/Contents/MacOS/src/debug/tserver/_sandbox.py", line 1, in <module>
# Used internally for debug sandbox under external interpreter
File "/Library/Frameworks/EPD64.framework/Versions/7.2/lib/python2.7/subprocess.py", line 493, in call
return Popen(*popenargs, **kwargs).wait()
File "/Library/Frameworks/EPD64.framework/Versions/7.2/lib/python2.7/subprocess.py", line 679, in __init__
errread, errwrite)
File "/Library/Frameworks/EPD64.framework/Versions/7.2/lib/python2.7/subprocess.py", line 1228, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
Just tried this and it made the shell crash.
Chicken="Chicken"
print Chicken
Chicken
call[("say %s" % (Chicken)]
That's not how string interpolation works.
cmd='cd %s' % (Desktop,)
First off,
cmd="'cd %s'(Desktop/)"
Doesn't seem like it would "printf" the %s.
Maybe
cmd="'cd %s/'%(Desktop)"
But I still don't know if that will interpolate since it's inside a string can using the "call" function and a python command -- wouldn't that call it on the command line?