Develop Reference

Python. Send Uploaded File To Remote Server

In My Flask App, i want to upload a file to a remote server.
i tried this code but i get an error
import subprocess
import os
c_dir = os.path.dirname(os.path.abspath(__file__))
myfile = open(c_dir + '\\cape-kid.png')
p = subprocess.Popen(["scp", myfile, destination])
sts = os.waitpid(p.pid, 0)
this was just a test file. there's an image in the same directory as my test python file. the error said:
Traceback (most recent call last): File
"C:\Users\waite-ryan-m\Desktop\remote-saving\test-send.py", line 20,
in
p = subprocess.Popen(["scp", c_dir + '\cape-kid.png', 'destination']) File
"C:\Users\waite-ryan-m\Desktop\WPython\WinPython-64bit-2.7.12.1Zero\python-2.7.12.amd64\lib\subprocess.py",
line 711, in init
errread, errwrite) File "C:\Users\waite-ryan-m\Desktop\WPython\WinPython-64bit-2.7.12.1Zero\python-2.7.12.amd64\lib\subprocess.py",
line 959, in _execute_child
startupinfo) WindowsError: [Error 2] The system cannot find the file specified

With open() you open an file to read or write on it. What you want is to concatinate the string and use this as parameter for scp. Maybe the file you want to copy also doesn't exist - have you tried printing the path you constructed and checking it manually?
And have you defined destination anywhere? This message could also mean, that the system cannot find scp.

subprocess.check_output(): OSError file not found in Python

Executing following command and its variations always results in an error, which I just cannot figure out:
command = "/bin/dd if=/dev/sda8 count=100 skip=$(expr 19868431049 / 512)"
print subprocess.check_output([command])
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/subprocess.py", line 566, in check_output
process = Popen(stdout=PIPE, *popenargs, **kwargs)
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
WHich file it is referring to ? other commands like ls,wc are running correctly though, the command is also running well on terminal but not python script.

Your command is a list with one element. Imagine if you tried to run this at the shell:
/bin/'dd if='/dev/'sda8 count=100 skip=$(expr 19868431049 '/' 512)'
That's effectively what you're doing. There's almost certainly no directory named dd if= in your bin directory, and there's even more almost certainly no dev directory under that with an sd8 count=100 skip=$(expr 19868431049 directory with a program named 512 in it.
What you want is a list where each argument is its own element:
command = ['/bin/dd', 'if=/dev/sda8', 'count=100', 'skip=$(expr 19868431049 / 512)']
print subprocess.check_output(command) # notice no []
But that brings us to your second problem: $(expr 19868431049 / 512) isn't going to be parsed by Python or by dd; that's bash syntax. You can, of course, just do the same thing in Python instead of in bash:
command = ['/bin/dd', 'if=/dev/sda8', 'count=100',
'skip={}'.format(19868431049 // 512)]
print subprocess.check_output(command)
Or, if you really want to use bash for no good reason, pass a string, rather than a list, and use shell=True:
command = "/bin/dd if=/dev/sda8 count=100 skip=$(expr 19868431049 / 512)"
print subprocess.check_output(command, shell=True) # still no []
Although that still isn't going to work portably, because the default shell is /bin/sh, which may not know how to handle bashisms like $(…) (and expr, although I think POSIX requires that expr exist as a separate process…). So:
command = "/bin/dd if=/dev/sda8 count=100 skip=$(expr 19868431049 / 512)"
print subprocess.check_output(command, shell=True, executable='/bin/bash')

This worked for me using subprocess.popen
command = "echo $JAVA_HOME"
proc = subprocess.Popen(command,stdout=subprocess.PIPE,shell=True)

Executing a vbs file with arguments created by python

I would like to convert dozens of excel sheets to csv files at once. I have a working .vbs file which makes the conversion, and I would like to execute this .vbs file on the different sheets with the help of a python code. I have the following 2 versions of the python code:
Version 1:
import os
import sys
import subprocess
FolderName=sys.argv[1]
FileList=os.listdir(FolderName)
NewList=[]
for i in FileList:
NewItem=i.split('.xls')
NewXls=FolderName+"\\"+NewItem[0]+".xlsx "
NewCsv=FolderName+"\\"+NewItem[0]+".csv"
NewCommand="C:\\Users\\user\\XlsToCsv.vbs "+sys.argv[2]+" "+NewXls+NewCsv
subprocess.call(NewCommand)
Version 2:
import os
import sys
import subprocess
def main(directory,extension,sheet):
for filename in os.listdir(directory):
if filename.endswith(extension):
path = os.path.join(directory, filename)
base = os.path.join(directory, filename[:len(filename)-len(extension)])
print base
new_xls = base + extension
new_csv = base + '.csv'
subprocess.call(['C:\\Users\\user\\XlsToCsv.vbs', sheet, new_xls, new_csv])
main(sys.argv[1],sys.argv[2],sys.argv[3])
It does not matter, which I try, I get the same error message:
Traceback (most recent call last):
File "C:/Users/user/Desktop/Work/XlsDir.py", line 16, in <module>
subprocess.call(NewCommand)
File "C:\Python27\lib\subprocess.py", line 524, in call
return Popen(*popenargs, **kwargs).wait()
File "C:\Python27\lib\subprocess.py", line 711, in __init__
errread, errwrite)
File "C:\Python27\lib\subprocess.py", line 948, in _execute_child
startupinfo)
WindowsError: [Error 193] %1 er ikke et gyldigt Win32-program
The last line of the error message means approximately, that it is not a valid Win32-program.
What I have tried so far:
If I run the .vbs file from command prompt with the right arguments (sheet, name of the .xls file and name of the .csv file) then it works fine.
If I print the commands that python generates and copy them into command prompt, they work fine.
I tried every combinations of '\' and '\' within the different paths, and nothing got any better.
I tried to execute the programs with replacing the sys.argv[i] arguments with specific arguments and then execute the .py file from command prompt. I get the same error message.
I hope some of you can help me. Thanks a lot!

To elaborate on Ansgar's remedy:
Starting a .vbs from the command line 'works', because the shell associates the extension .vbs with an application (e.g. cscript/wscript; see ftype, assoc, cscript //E, cescript //S).
subprocess.call() does not open a shell, so either specify the application (c|wscript.exe) or start the shell yourself:
import subprocess
#subprocess.call("notepad") # works
#subprocess.call("dir") # [Error 2] The system cannot find the file specified
# no shell, no intrinsics
#subprocess.call("19112944.vbs") # [Error 193] %1 is not a valid Win32 application
# no shell, can't associate .vbs with c|wscript.exe
subprocess.call("cscript 19112944.vbs") # works
subprocess.call("cmd /c 19112944.vbs") # works
# have shell, can associate .vbs with c|wscript.exe

Try running the script with cscript.exe:
subprocess.call(['cscript.exe', 'C:\\Users\\user\\XlsToCsv.vbs', sheet, new_xls, new_csv])

How to use the dir/s command in Python?

Background
I use the command dir/s in batch files all the time. But, I am unable to call this using python. NOTE: I am using Python 2.7.3.
Code
import subprocess
subprocess.call(["dir/s"])
Error Message
Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
subprocess.call(["dir/s"])
File "C:\Python27\lib\subprocess.py", line 493, in call
return Popen(*popenargs, **kwargs).wait()
File "C:\Python27\lib\subprocess.py", line 679, in __init__
errread, errwrite)
File "C:\Python27\lib\subprocess.py", line 896, in _execute_child
startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
I have tried changing the quotations but nothing has worked.
How would I call the dir/s module using subprocess?

How about
subprocess.call("dir/s", shell=True)
Not verified.

This is a lot different than what you're asking but it solves the same problem. Additionally, it solves it in a pythonic, multiplatform way:
import fnmatch
import os
def recglob(directory, ext):
l = []
for root, dirnames, filenames in os.walk(directory):
for filename in fnmatch.filter(filenames, ext):
l.append(os.path.join(root, filename))
return l

You need a space between dir and /s. So break it into an array of 2 elements. Also as carlosdoc pointed out, you would need to add shell=True, since the dir command is a shell builtin.
import subprocess
subprocess.call(["dir", "/s"], shell=True)
But if you're trying to get a directory listing, make it OS independent by using the functions available in the os module such as os.listdir(), os.chdir()

I finally found the answer. To list all directories in a directory (e.g. D:\\, C:\\) on needs to first import the os module.
import os
Then, they need to say that they want to list everything. Within that, they need to make sure that the output is printed.
for top, dirs, files in os.walk('D:\\'):
for nm in files:
print os.path.join(top, nm)
That was how I was able to solve it. Thanks to this.

As it's an inbuilt part of the command line you need to run it as:
import subprocess
subprocess.call("cmd /c dir /s")

Popen error: "[Errno 2] No such file or directory" when calling shell function

I have some custom commands.
This works:
subprocess.Popen(['python'], stdout=subprocess.PIPE)
But if I have my own system commands like deactivate, I get that error
Traceback (most recent call last):
File "runner2.py", line 21, in <module>
main()
File "runner2.py", line 18, in main
subprocess.Popen(['deactivate',], stdout=subprocess.PIPE)
File "/usr/lib/python2.6/subprocess.py", line 633, in __init__
errread, errwrite)
File "/usr/lib/python2.6/subprocess.py", line 1139, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
Let alone I need to execute this under my sandbox virtualenv.

Try add an extra parameter shell=True to the Popen call.

Just a note. shell=True was likely the correct solution to the o.p., since they did not make the following mistake, but you can also get the "No such file or directory" error if you do not split up your executable from its arguments.
import subprocess as sp, shlex
sp.Popen(['echo 1']) # FAILS with "No such file or directory"
sp.Popen(['echo', '1']) # SUCCEEDS
sp.Popen(['echo 1'], shell=True) # SUCCEEDS, but extra overhead
sp.Popen(shlex.split('echo 1')) # SUCCEEDS, equivalent to #2
Without shell=True, Popen expects the executable to be the first element of args, which is why it fails, there is no "echo 1" executable. Adding shell=True invokes your system shell and passes the first element of args to the shell. i.e. for linux, Popen(['echo 1'], shell=True) is equivalent to Popen('/bin/sh', '-c', 'echo 1') which is more overhead than you may need. See Popen() documentation for cases when shell=True is actually useful.

You have to give the full path to your program deactivate and then it the subprocess module should be able to find it.

I'm spawning subprocesses like that:
SHUTDOWN_CMD = os.path.sep.join(["c:", "windows", "system32", "shutdown.exe"])
def abortShutdown():
os.spawnv(os.P_NOWAIT, SHUTDOWN_CMD,
[SHUTDOWN_CMD, '/A'])
time.sleep(3)
I'm not using subprocess since Python 2.5 does not support it. I had to use use the FULL path to have it working and I guess you also have to use the full path to your custom commands.