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.
0
Related
I am trying to use PyExifTool to examine the EXIF data of given images. I am using an almost identical copy of what can be found in the github support documents and another StackOverflow resource.
This is what my code looks like:
import exiftool
import os, errno
files = ["/Users/username/Pictures/testimage.jpg"]
with exiftool.ExifTool() as et:
metadata = et.get_tag('DateCreated', files)
print(metadata)
I then receive quite the error message. As I am very new to coding I am struggling to troubleshoot this response.
Traceback (most recent call last):
File "/Users/username/Documents/test.py", line 7, in <module>
with exiftool.ExifTool() as et:
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/exiftool.py", line 191, in __enter__
self.start()
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/exiftool.py", line 170, in start
self._process = subprocess.Popen(
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/subprocess.py", line 854, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/subprocess.py", line 1702, in _execute_child
raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'exiftool'
Presumably, the key piece of information here is:
FileNotFoundError: [Errno 2] No such file or directory: 'exiftool'
Except that I don't really understand what I am being told? ExifTool is supposed to be a tool, I am not intentionally trying to access it as a file or directory.
I can be certain ExifTool is correctly installed because if in command line I run...
#bash:~
$ exiftool /Users/username/Pictures/testimage.jpg
...ExifTool returns all the Exif data for my test image including an in-tact 'Date Created' field. Incidentally, this also confirms that my path is correct.
Edit 1: Additional information as per the request of tripleee
(Excuse my ignorance if and when I give the wrong information)
- How do I run the script?
-> I just have that snippet of code in a .py document and then it runs in my idle shell?
- Running type -all exiftool in Bash
exiftool is /usr/local/bin/exiftool
exiftool is /usr/local/bin/exiftool
(yes it does give the same thing twice)
- Running print(os.environ['PATH']) in IDLE
/usr/bin:/bin:/usr/sbin:/sbin
Edit 2: Additional troubleshooting off the back of Tripleee's queries
- Running type -all exiftool in Bash gave two paths.
exiftool is /usr/local/bin/exiftool
exiftool is /usr/local/bin/exiftool
--> I used some code I found elsewhere to try and fix this.
PATH=$(printf "%s" "$PATH" | awk -v RS=':' '!a[$1]++ { if (NR > 1) printf RS; printf $1 }')
Now running type -all exiftool in Bash gives only...
exiftool is /usr/local/bin/exiftool
Until I open a new terminal window/tab, a which point the problem returns.
- How do I run the script?
Well now I open terminal and input IDLE3 so that it is opened from prompt, not via the icon on my hotbar.
This gives a new error...
Traceback (most recent call last):
File "/Users/username/Documents/test.py", line 9, in <module>
metadata = et.get_tag('Date Created', files)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/exiftool.py", line 325, in get_tag
return self.get_tag_batch(tag, [filename])[0]
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/exiftool.py", line 312, in get_tag_batch
data = self.get_tags_batch([tag], filenames)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/exiftool.py", line 291, in get_tags_batch
return self.execute_json(*params)
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/exiftool.py", line 252, in execute_json
return json.loads(self.execute(b"-j", *params).decode("utf-8"))
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/exiftool.py", line 108, in fsencode
return filename.encode(encoding, errors)
AttributeError: 'list' object has no attribute 'encode'
The key difference being it ends:
AttributeError: 'list' object has no attribute 'encode'
Edit 3: Additional troubleshooting off the back of Tripleee's queries
- Discovered I had added nano .bash_profile to the end of my .bash_profile.
--> This has been removed
- Running print(os.environ['PATH']) in IDLE but now from prompt using IDLE3
/Library/Frameworks/Python.framework/Versions/3.8/bin:/usr/local/fsl/bin:/usr/local/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin~/.bash_profile
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
Let us consider Linux platform where I need to execute a program called smart.exe which uses input.dat file. Both the files are placed in the same directory with each file having the same file permission 777.
Now if I run the following command in the terminal window smart.exe is fully executed without any error.
$./smart.exe input.dat
On the other hand, if I use the following python script called my_script.py placed in the same directory, then I get an error.
my_script.py has the following code:
#!/usr/bin/python
import os, subprocess
exit_code = subprocess.call("./smart.exe input.dat", shell = False)
The error is as follows:
File "my_script.py", line 4, in <module>
exit_code = subprocess.call("./smart.exe input.dat", shell = False)
File "/usr/lib64/python2.6/subprocess.py", line 478, in call
p = Popen(*popenargs, **kwargs)
File "/usr/lib64/python2.6/subprocess.py", line 642, in __init__
errread, errwrite)
File "/usr/lib64/python2.6/subprocess.py", line 1234, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
Can someone please tell me why this is happening. Please note that the smart.exe should take around 10 sec to fully complete. This may be a clue for the problem.
Please also advise if there is any other way to run smart.exe from my_script.py. Your solution is much appreciated!
You should decide if you want shell support or not.
If you want the shell to be used (which is not necessary here), you should use exit_code = subprocess.call("./smart.exe input.dat", shell=True). Then the shell interprets your command line.
If you don't want it (as you don't need it and want to avoid unnecessary complexity), you should do exit_code = subprocess.call(["./smart.exe", "input.dat"], shell=False).
(And there is no point naming your binarys .exe under Linux.)
I am trying to use this example script to test crontab in python:
from crontab import CronTab
tab = CronTab(user='www',fake_tab='True')
cmd = '/var/www/pjr-env/bin/python /var/www/PRJ/job.py'
cron_job = tab.new(cmd)
cron_job.minute().every(5)
#writes content to crontab
tab.write()
print tab.render()
It returns with an error 'fake_tab' not defined. If i remove this parameter and call the function
like this: CronTab(user='www'). I returns the following error :
Traceback (most recent call last):
File "<pyshell#8>", line 1, in <module>
tab = CronTab(user='www')
File "C:\Python27\lib\site-packages\crontab.py", line 160, in __init__
self.read(tabfile)
File "C:\Python27\lib\site-packages\crontab.py", line 183, in read
p = sp.Popen(self._read_execute(), stdout=sp.PIPE)
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 2] The system cannot find the file specified
Does any one know, what am I missing?
I think that Crontab is a Unix/Linux concept. Not sure if it can work under windows. This Page says "Windows support works for manual crontabs only". Not sure what he means by that though.
As the author of python-crontab I can report that the documentation has been updated. It's clear ineffective given the number of people puzzled over what manual means.
If you do this:
mem_cron = CronTab(tab="""
* * * * * command # comment
""")
You should have a memory only crontab. Same if you do a file as a crontab:
file_cron = CronTab(tabfile='filename.tab')
I'm always looking to improve the code and documentation, so please do email me.
The easiest way I found to make crontab find my job was:
In settings.py (I'm using django) I defined these variables:
CRONTAB_EXECUTABLE='C:/Users/myuser/myvirtualenv/Lib/site-packages/django_crontab/crontab.py'
CRONTAB_DJANGO_PROJECT_NAME='myproject'
CRONTAB_DJANGO_MANAGE_PATH='C:/Users/myuser/myvirtualenv/myproject/manage.py'
CRONTAB_PYTHON_EXECUTABLE='C:/Users/myuser/AppData/Local/Programs/Python/Python36-32/pythonw.exe'
Pay attention to the slash. It must be leaned to the right or it causes a syntax error.
By this way crontab will find the job or whatever you are trying to execute. In my case I was trying:
C:\Users\bsi\mlearning3\src>python manage.py crontab add
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?