The objective is to receive an image path and pass that to a Python program as an argument, then receive the results.
This is done through a web app using VB (on the IIS server) and it works perfectly except when I import the python module OpenCV (imported in Python as cv2, more specifically).
What's even more confusing is that the script runs perfectly with the imported cv2 module when executed directly from cmd. It only fails to work when the VB code runs the script including the line import cv2.
I'll show some code below, for clarity.
VB code running Python script with image path as an argument:
Dim Processtask As New System.Diagnostics.Process()
Processtask.StartInfo.FileName = "cmd.exe"
Processtask.StartInfo.Arguments = "/c python " + path.ToString + " " + ImageURL.ToString
Processtask.StartInfo.UseShellExecute = False
Processtask.StartInfo.RedirectStandardOutput = True
Processtask.StartInfo.RedirectStandardError = True
Processtask.StartInfo.CreateNoWindow = True
Processtask.Start()
Processtask.WaitForExit()
output = Processtask.StandardOutput.ReadToEnd()
Python code snippet receiving image path:
import sys
import cv2
if __name__ == "__main__":
im = str(sys.argv[1])
print(im)
I have run out of possible ideas as to what could cause this problem. Any advice would be greatly appreciated.
EDIT
I managed to find the full error message which reads as follows:
System.Exception: System.IO.StreamReader
System.InvalidOperationException: Process has exited, so the requested
information is not available.
at System.Diagnostics.Process.EnsureState(State state) at
System.Diagnostics.Process.get_ProcessName()
at System.Diagnostics.Process.ToString()
Got the solution eventually, I'll post it here in case anyone else ever runs into this problem:
The dll files of opencv installed onto the server which hosted the web app had different access rights. The files were denied access when being called from the web application, whereas the rest of the modules called had no issue.
I used sysinternals process monitor to trace which files were being denied access and was able to change the rights by hand. Not very elegant but it worked out.
I have a tool I wrote in python that works completely fine when running in the maya script editor. However, I want to be able to import the script from the script directory. Which should be simple, and I am shocked I can't find the solution while searching the web.
My script format is like this example:
import maya.cmds as cmds
# GUI code with buttons, they call the functions below.
#
#
def function1():
#commands that do things
def function2():
#commands that do things
#List of functions continues
Like I said, the program functions perfectly when run in the script editor. When saving the script to the directory and using this method:
import module
reload (module)
module.function()
The GUI loads fine, but then when pushing the gui buttons, it says the functions are not defined. I don't understand what I am missing? If the script was loaded, shouldn't the functions be defined? Any help would be greatly appreciated, thank you!
Just because the GUI loads doesn't mean that all of your functions loaded properly. You need to put your file, (module.py) in a directory that is visible to your PYTHONPATH. If you're in Maya, you can also put it in the MAYA_SCRIPT_PATH
The PYTHONPATH / MAYA_SCRIPT_PATH are environment variables that you set before launching Maya. In a default Maya installation, some places where you could put your module.py file would be:
(Windows) C:\Users\YOUR_USER_NAME\Documents\maya\scripts
(Linux) ~/maya/scripts
(Mac) - Not sure, put probably also ~/maya/scripts
If you want to know where else you can place it, you run this
import os
print(os.getenv('MAYA_SCRIPT_PATH', ''))
print(os.getenv('PYTHONPATH', ''))
Any location in that list that you have write permissions to is OK to add your module.py file.
Also, it's worth noting that in your example module.function() would fail. It'd need to be module.function1() or module.function2() but I assume you know that. Hope this helps
Sup guys
So i know this is an old question that has already been answered but I have some extra information that helps in regards to GUI functions not working. (same error)
and there's basically nothing on this anywhere.
so the script director only helps when loading in the module through the shelf but will still return the same error "fuction is not defined"
this has todo with how the function is called through the UI element.
example.
this is will allow you to call function in the script editor
but gives you the function not defined error when the module is imported
def GUI_function():
pm.button( command = "function()")
def function():
do stuff
this on the other hand works.
def GUI_function():
pm.button( command = function)
def function(*_):
do stuff
i don't know why but maya tends to think function() is a nodetype
so remove the brackets if you not using arguments and you good to go
I am using python 2.4 for a program which imports scripts from the internet and executes them so a script could be changed by the author and the user wouldn't have to re-download the script.
This is the part of the program that downloads the script:
def downloadScript(self,script):
myfile=open('#A file path/'+script['name']+'.txt','w')
try:
downloadedScript=urllib.urlopen(script['location']).read()
except:
#raise error
return
myfile.write(downloadedScript)
myfile.close()
def loadScript(self):
if not self.scriptCurrentlyLoaded:
script=self.scripts[self.scroller.listPos]
if script['location']=='None':
#raise error
return
self.downloadScript(script)
myfile=open('#A file path/'+script['name']+'.txt','r')
for line in myfile:
if line.startswith('from') or line.startswith('import'):
exec(line.strip()) #This was added because of the name errors
#being produced but to no affect
myfile.close()
execfile('#A file path/'+script['name']+'.txt')
self.scriptCurrentlyLoaded=True
self.scriptLoaded=script
else:
#raise error
The very odd thing is that when I run
execfile(script path)
outside of the function, after the script has been downloaded, the script is executed correctly. But trying to run the loadScript function raises name errors in the script even though the names have been imported in the script and before the execfile which I find very odd.
So my question is: Am I using a very bad method to download and execute these scripts?
Sorry if this question was answered before but I can't seem to find anyone else who is trying to run python scripts by downloading them from the internet.
Edit: adding globals as another argument to the execfile has seemed to fix the problem for now. I don't know if any other problems will occur later though.
In R you can simply 'source(url)'. Here's the closest I have found so far in python:
import urllib
(fn,hd) = urllib.urlretrieve('http://host.com/file.py')
execfile(fn)
I just started with Python and I'm having some problems. I've written already a few scripts for ArcGIS and had some recurring stuff. So I thought it would be smart to put that in modules which I can easily use again.
So now I have two scripts, script.py and toolbox.py.
My script was working fine so I copied and paste the part I needed, edited it a bit and everything goes well except for the messages created with gp.Addmessage
script.py will create the message "Hello Stackoverflow" but the messages from toolbox.py doesn't show up. Why is that? It loads the toolbox because I can use it later on, so it regocnizes the gp object.
I'm kind of stuck here, would love to be able to print messages from inside the modules to inform the user of the tool what is happening.
script.py:
import os, sys, arcgisscripting
# Create the Geoprocessor object
gp = arcgisscripting.create()
gp.AddMessage("# Hello Stackoverflow")
import toolbox
toolbox.loadToolbox
toolbox.py:
def loadToolbox:
try:
some code
gp.AddToolbox(path)
gp.AddMessage("# Toolbox loaded")
except:
gp.AddMessage("# Toolbox not found")
You have two problems with your code:
You never call the loadToolBox method, you only refer to it. Add ():
toolbox.loadToolbox()
Your loadToolbox() function doesn't take gp as an argument. If gp is meant to be a global, then it won't be visible to the toolbox module (globals are only visible in the current module).
Add gp as a parameter and pass it in when calling loadToolbox. In script.py:
toolbox.loadToolbox(gp)
and in toolbox.py:
def loadToolbox(gp):
# rest of function
Imagine a python script that will take a long time to run, what will happen if I modify it while it's running? Will the result be different?
Nothing, because Python precompiles your script into a PYC file and launches that.
However, if some kind of exception occurs, you may get a slightly misleading explanation, because line X may have different code than before you started the script.
When you run a python program and the interpreter is started up, the first thing that happens is the following:
the module sys and builtins is initialized
the __main__ module is initialized, which is the file you gave as an argument to the interpreter; this causes your code to execute
When a module is initialized, it's code is run, defining classes, variables, and functions in the process. The first step of your module (i.e. main file) will probably be to import other modules, which will again be initialized in just the same way; their resulting namespaces are then made available for your module to use. The result of an importing process is in part a module (python-) object in memory. This object does have fields that point to the .py and .pyc content, but these are not evaluated anymore: module objects are cached and their source never run twice. Hence, modifying the module afterwards on disk has no effect on the execution. It can have an effect when the source is read for introspective purposes, such as when exceptions are thrown, or via the module inspect.
This is why the check if __name__ == "__main__" is necessary when adding code that is not intended to run when the module is imported. Running the file as main is equivalent to that file being imported, with the exception of __name__ having a different value.
Sources:
What happens when a module is imported: The import system
What happens when the interpreter starts: Top Level Components
What's the __main__ module: __main__- Top-level code environment
This is a fun question. The answer is that "it depends".
Consider the following code:
"Example script showing bad things you can do with python."
import os
print('this is a good script')
with open(__file__, 'w') as fdesc:
fdesc.write('print("this is a bad script")')
import bad
Try saving the above as "/tmp/bad.py" then do "cd /tmp" and finally "python3 bad.py" and see what happens.
On my ubuntu 20 system I see the output:
this is a good script
this is a bad script
So again, the answer to your question is "it depends". If you don't do anything funky then the script is in memory and you are fine. But python is a pretty dynamic language so there are a variety of ways to modify your "script" and have it affect the output.
If you aren't trying to do anything funky, then probably one of the things to watch out for are imports inside functions.
Below is another example which illustrates the idea (save as "/tmp/modify.py" and do "cd /tmp" and then "python3 modify.py" to run). The fiddle function defined below simulates you modifying the script while it is running (if desired, you could remove the fiddle function, put in a time.sleep(300) at the second to last line, and modify the file yourself).
The point is that since the show function is doing an import inside the function instead of at the top of the module, the import won't happen until the function is called. If you have modified the script before you call show, then your modified version of the script will be used.
If you are seeing surprising or unexpected behavior from modifying a running script, I would suggest looking for import statements inside functions. There are sometimes good reasons to do that sort of thing so you will see it in people's code as well as some libraries from time to time.
Below is the demonstration of how an import inside a function can cause strange effects. You can try this as is vs commenting out the call to the fiddle function to see the effect of modifying a script while it is running.
"Example showing import in a function"
import time
def yell(msg):
"Yell a msg"
return f'#{msg}#'
def show(msg):
"Print a message nicely"
import modify
print(modify.yell(msg))
def fiddle():
orig = open(__file__).read()
with open(__file__, 'w') as fdesc:
modified = orig.replace('{' + 'msg' + '}', '{msg.upper()}')
fdesc.write(modified)
fiddle()
show('What do you think?')
No, the result will not reflect the changes once saved. The result will not change when running regular python files. You will have to save your changes and re-run your program.
If you run the following script:
from time import sleep
print("Printing hello world in: ")
for i in range(10, 0, -1):
print(f"{i}...")
sleep(1)
print("Hello World!")
Then change "Hello World!" to "Hello StackOverflow!" while it's counting down, it will still output "Hello World".
Nothing, as this answer. Besides, I did experiment when multiprocessing is involved. Save the script below as x.py:
import multiprocessing
import time
def f(x):
print(x)
time.sleep(10)
if __name__ == '__main__':
with multiprocessing.Pool(2) as pool:
for _ in pool.imap(f, ['hello'] * 5):
pass
After python3 x.py and after the first two 'hello' being printed out, I modified ['hello'] to ['world'] and observed what happend. Nothing interesting happened. The result was still:
hello
hello
hello
hello
hello
It happens nothing. Once the script is loaded in memory and running it will keep like this.
An "auto-reloading" feature can be implemented anyway in your code, like Flask and other frameworks does.
This is slightly different from what you describe in your question, but it works:
my_string = "Hello World!"
line = input(">>> ")
exec(line)
print(my_string)
Test run:
>>> print("Hey")
Hey
Hello World!
>>> my_string = "Goodbye, World"
Goodbye, World
See, you can change the behavior of your "loaded" code dynamically.
depending. if a python script links to other modified file, then will load newer version ofcourse. but if source doesnt point to any other file it'll just run all script from cache as long as its run. changes will be visible next time...
and if about auto-applying changes when they're made - yes, #pcbacterio was correct. its possible to do thar but script which does it just remembers last action/thing what was doing and checks when the file is modified to rerun it (so its almost invisible)
=]