Python: Can't find file even though file referenced exists - python

I'm getting this error when trying to run a Python script. Is it saying that it can't find subprocess.py? Because I found it in the location it's listing there, so I doubt that's the issue. What file can't it find?
Traceback (most recent call last):
File "D:\Projects\PythonMathPlots\MandelbrotVideoGenerator.py", line 201, in <module>
run( ['open', 'MandelbrotZoom.mp4'] )
File "C:\Users\Aaron\AppData\Local\Programs\Python\Python37\lib\subprocess.py", line 472, in run
with Popen(*popenargs, **kwargs) as process:
File "C:\Users\Aaron\AppData\Local\Programs\Python\Python37\lib\subprocess.py", line 775, in __init__
restore_signals, start_new_session)
File "C:\Users\Aaron\AppData\Local\Programs\Python\Python37\lib\subprocess.py", line 1178, in _execute_child
startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified

You may need to put the full path in the run(...) command, to the open file, and the path to the .mp4 file as well.
Most likely, open does not exist on your system and you have to use the name of the video player software instead.

Make sure the user you're running the script as has read permission for the file.

You may also try with subprocess.Popen(args, shell=True). The use of shell=True may be useful.
Also, use a path defined as path = os.path.join(filepath, filename) and then before passing the path to Popen, assert if os.path.exists(path)==True.
But note that there are some downsides to using shell=True:
Actual meaning of 'shell=True' in subprocess
https://medium.com/python-pandemonium/a-trap-of-shell-true-in-the-subprocess-module-6db7fc66cdfd

Related

How to merge audio and video file using ffmpeg in python?

I need to merge both audio and video using ffmpeg in python 3.7,could you help me to solve this issue?
Here i used code :
from pathlib import Path
glob_path = Path(r"D:\t")
file_name = [str(pp) for pp in glob_path.glob(r'**/*.mp4')]
print(file_name)
video_stream = ffmpeg.input(file_name[0])
audio_stream = ffmpeg.input(file_name[1])
print(video_stream)
print(audio_stream)
ffmpeg.output(audio_stream, video_stream, 'out.mp4').run()
I getting this out put error
['D:\\t\\audio.mp4', 'D:\\t\\video.mp4']
input(filename='D:\\t\\audio.mp4')[None] <b0ebefda3dca>
input(filename='D:\\t\\video.mp4')[None] <388c87446fd1>
Traceback (most recent call last):
File "C:\Users\LENOVO\PycharmProjects\calc_new\udownlod.py", line 18, in <module>
ffmpeg.output(audio_stream, video_stream, 'out.mp4').run()
File "C:\Users\LENOVO\PycharmProjects\calc_new\venv\lib\site-packages\ffmpeg\_run.py", line 320, in run
overwrite_output=overwrite_output,
File "C:\Users\LENOVO\PycharmProjects\calc_new\venv\lib\site-packages\ffmpeg\_run.py", line 285, in run_async
args, stdin=stdin_stream, stdout=stdout_stream, stderr=stderr_stream
File "C:\Users\LENOVO\Anaconda3\lib\subprocess.py", line 775, in __init__
restore_signals, start_new_session)
File "C:\Users\LENOVO\Anaconda3\lib\subprocess.py", line 1178, in _execute_child
startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified
Looks like one of the files cannot be found. The best thing to do is to check if both files exist at the specified locations.
FileNotFoundError: [WinError 2] The system cannot find the file specified
Even though it was shown path error, that error was in installation package, i used
conda install -c menpo ffmpeg
in https://anaconda.org/menpo/ffmpeg , solved my issue

Python subprocess FileNotFoundError

I am trying to follow this blog on how to execute an R script from Python. I have the R script working fine from the command line using Rscript.
Here's my Python code:
import subprocess
import os
command = "C:\Program Files\R\R-3.4.4\bin\Rscript"
path2script = os.getcwd() + "\max.R" # gives me the absolute path to the R script
args = ["11", "3", "9", "42"]
cmd = [command, path2script] + args
x = subprocess.check_output(cmd, universal_newlines = True)
Which gives me this error:
FileNotFoundError: [WinError 2] The system cannot find the file specified
I've read a lot of SO posts on this error and in most cases it seems to be a problem with trying to invoke system commands like dir or passing arguments to check_output in the wrong order but in my case I really don't see what should be going wrong.
Following some of the advice I've tried building a string for cmd instead of a list, and then passing it to check_output using the argument shell = True - when I do that I get a CalledProcessError: returned non-zero exit status 1.
I'm assuming this code, which is exactly as it appeared on the blog other than adding the absolute path to the file, is failing now because the behaviour of check_output has changed since 2015...
Can anyone help?
Here's the stack trace:
Traceback (most recent call last):
File "<ipython-input-2-3a0151808726>", line 1, in <module>
runfile('C:/Users/TomWagstaff/Documents/Raising IT/Projects/15 AdWords/Python_R_test/run_max.py', wdir='C:/Users/TomWagstaff/Documents/Raising IT/Projects/15 AdWords/Python_R_test')
File "C:\Users\TomWagstaff\Anaconda3\envs\adwords\lib\site-packages\spyder\utils\site\sitecustomize.py", line 705, in runfile
execfile(filename, namespace)
File "C:\Users\TomWagstaff\Anaconda3\envs\adwords\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
exec(compile(f.read(), filename, 'exec'), namespace)
File "C:/Users/TomWagstaff/Documents/Raising IT/Projects/15 AdWords/Python_R_test/run_max.py", line 31, in <module>
x = subprocess.check_output(cmd, universal_newlines = True)
File "C:\Users\TomWagstaff\Anaconda3\envs\adwords\lib\subprocess.py", line 336, in check_output
**kwargs).stdout
File "C:\Users\TomWagstaff\Anaconda3\envs\adwords\lib\subprocess.py", line 403, in run
with Popen(*popenargs, **kwargs) as process:
File "C:\Users\TomWagstaff\Anaconda3\envs\adwords\lib\site-packages\spyder\utils\site\sitecustomize.py", line 210, in __init__
super(SubprocessPopen, self).__init__(*args, **kwargs)
File "C:\Users\TomWagstaff\Anaconda3\envs\adwords\lib\subprocess.py", line 709, in __init__
restore_signals, start_new_session)
File "C:\Users\TomWagstaff\Anaconda3\envs\adwords\lib\subprocess.py", line 997, in _execute_child
startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified
check that you have a right path for command and script
print(os.path.exists(command))
print(os.path.exists(path2script))
note that writing path with backslashes may be dangerous as you can create escape sequence that way which will be interpreted in different way. You can write windows paths with forward slashes and then call os.path.normpath on them, turning them into safe form
(also in command you can use forward slashes only, Python interpret doesn't really care. In path to your R script that would be probably problem though)

using Python to send subprocess commands with escape characters

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)')

subprocess error message:[Errno 2] in _execute_child raise child_exception

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'].

cp: cannot stat ... No such file or directory

In a python script, I issue the command:
def copy_file(csv_file): #csv_file = "wpa-01.csv"
subprocess.call(["cp",csv_file,"tempfile.csv"])
I get the error:
cp: cannot stat 'wpa-01.csv' : No such file or directory
-tempfile.csv is a valid file, it is open
-I have tried adding quotes around wpa-01.csv, ie
subprocess.call(["cp","\"wpa-01.csv\"","tempfile.csv"])
-I have tried adding escape character in front of the '-'
-I have tried including the directory in front og the file name
-I am using gedit on a local Linux machine (so its not a dos2unix kind of solution), but the script is being ran on a remote Raspberry Pi
in every case I get the same error. I am at a loss for solutions. any suggestions?
***Here is the problem: "wpa-01.csv" is a 'live'/'dynamic' file. There is an active process that is updating that file in real time. I think that the file will have to be 'dead'/'static' in order to issue cp command? This is not ideal for my purposes. Is there a way to work around this like changing the mod or something? If not I suppose I can try to find an alternative solution.
print "wpa-01.csv" in os.listdir(".") #make sure file really does exist
subprocess.call(["cp","\"wpa-01.csv\"","tempfile.csv"],shell=True)
My guess is you need to set shell=True so that it uses your path to find cp executes in your shell ... if you don't use shell=True it wont use your path ...
Unfortunately all it is is a guess ...
Anyway, here is some supporting evidence:
>>> subprocess.call("copy tmp5.py tmp55.py")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python26\lib\subprocess.py", line 470, in call
return Popen(*popenargs, **kwargs).wait()
File "C:\Python26\lib\subprocess.py", line 623, in __init__
errread, errwrite)
File "C:\Python26\lib\subprocess.py", line 833, in _execute_child
startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
>>> subprocess.call("copy tmp5.py tmp55.py",shell=True)
1 file(s) copied.
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