My code is running without calling variable in Python? - python

When I run the below code my websites or steam still open. Shouldn't I need to state print(link) or print(steam) for them to open?
import os
import webbrowser
import subprocess
import random
urls = ['https://www.ft.com/',
'https://www.youtube.com/watch?v=xvqcFcfhUVQ',
'https://roadmap.sh/backend',
'https://www.youtube.com/watch?v=YYXdXT2l-Gg&list=PL-osiE80TeTskrapNbzXhwoFUiLCjGgY7']
foxpath = 'C:/Program Files/Mozilla Firefox/Firefox.exe %s'
link = webbrowser.get(foxpath).open(random.choice(urls))
steam = subprocess.call(['C:/Program Files (x86)/Steam/Steam.exe'])
Why does this happen?
I eventually want to run the program from a function call, like below.
def wildcard():
print(random.choice(link, steam))
wildcard()

No, there is nothing special about print. print is just a function that takes in some value and displays it to the user.
If you had instead steam = 3 * 4, would you be surprised to learn that the value 12 is computed, and steam becomes a name for that value, even if you don't do anything with it? It's the same thing here - calling subprocess.call causes the program to launch, and it has nothing to do with the name steam, nor anything that you do or don't do with that name subsequently.
If you were to add the print(steam) line that you have in mind, what it would display (after you close steam and control returns to your program) is the "return code" of that program - this gets into the details of how your operating system works, but most likely it would be something like 0.
If you want something that you can later call in order to launch Steam - well, that's a function. Like you already know how to do:
def steam():
subprocess.call(['C:/Program Files (x86)/Steam/Steam.exe'])

As soon as you issue webbrowser.get or subprocess.call, they execute. Your variables are really storing the return values of those functions, not aliases to those function calls.
If you want to alias the function calls as it appears you are intending, you could do something like this:
def open_link():
return webbrowser.get(foxpath).open(random.choice(urls))
def open_steam():
return subprocess.call(['C:/Program Files (x86)/Steam/Steam.exe'])
Then your top level would be:
def wildcard():
random.choice([link, steam])()
wildcard()
Note the syntax difference for choosing the functions randomly. See this answer for more clarification.

You do invoke something:
steam = subprocess.call(['C:/Program Files (x86)/Steam/Steam.exe'])
The documentation for subprocess.call is clear on what the call method does: it invokes the given argument as a subprocess.

The problem is that your code isn't inside a function, so, when you execute it, it runs all the diretives including
steam = subprocess.call(['C:/Program Files (x86)/Steam/Steam.exe'])
Which calls C:/Program Files (x86)/Steam/Steam.exe, opening your steam app.
Hope it helps.

Thank you, I understand now. I actually just resolved the problem with the following
def wildcard():
for x in range(1):
rand = random.randint(1, 10)
if rand > 5:
link = webbrowser.get(foxpath).open(random.choice(urls))
else:
subprocess.call(['C:/Program Files (x86)/Steam/Steam.exe'])
wildcard()

Related

How do I call a function in vs code using python?

I'll want to know how to call a function in vs code. I read the answer to similar questions, but they don't work:
def userInput(n):
return n*n
userInput(5)
And appends nothing
def Input(n):
return n*n
And in the terminal:
from file import *
from: can't read /var/mail/file
Can somebody help me?
You are doing everything correctly in the first picture. In order to call a function in python on vs code you first have to define the function, which you did by typing def userInput(n):. If you want to see the result of your function, you should not use return, you should use print instead. Return is a keyword- so when your computer reaches the return keyword it attempts to send that value from one point in your code to another. If you want to see the result of your code, typing print (n) would work better.
Your code should look like this:
def userInput(n):
print (n * n)
userInput(5)
The code would print the result 25
Your terminal is your general way to access your operating system, so you have to tell it that you want it to interpret your Python code first.
If you want to run the file you're typing in, you have to first know the location of that file. When you type ls in your terminal, does the name of your Python file show up? If not, hover over the tab in VSCode (it's close to the top of the editor) and see what path appears. Then in your terminal type cd (short for "change directory") and then the path that you saw, minus the <your filename here>.py bit. Type ls again, and you should see your Python file. Now you can type python <your filename here>.py to run it (provided you have Python installed).
You could also run the IDLE by just typing python in your terminal. This will allow you to write your code line-by-line and immediately evaluate it, but it's easier to write in VSCode and then run it with the method I described before.

python script that takes command line arguments needs to be called from another python script

I completely understand that I should have written the script right the first time, but the fact is I have a script that generates a data file based upon two values passed to it from the command line- like this:
[sinux1~]: ./sim_gen.py 100 .3
I need to call this script from within another script, iterating over a range of values. I searched around and after navigating through all of the "you shouldn't," I tried :
exec(open("./sim_gen.py 100 .3").read())
And this doesn't seem to work.
Help?
Let's break this down into pieces:
exec(open("./sim_gen.py 100 .3").read())
This is equivalent to:
f = open("./sim_gen.py 100 .3")
contents = f.read()
exec(contents)
That open is the same open you use for, say, reading a text file or a CSV. You're asking for a file named "sim_gen.py 100 .3" in the current directory. Do you have one? Of course not. So the open fails.
The best solution is, as you already know, to rewrite sim_gen.py so that you can import it and call a function and pass the arguments to it.
Failing that, the cleanest answer is probably to just run the Python script as a subprocess:
import subprocess
import sys
subprocess.run([sys.executable, "./sim_gen.py", "100", ".3"])
Notice that this is effectively the same thing you're doing when you run the script from your shell, so if it was OK there, it's almost surely OK here.
If you really need to exec for some reason, you will need to do something really hacky, and temporarily change argv for that script's code:
import sys
_argv = sys.argv
try:
sys.argv = ["./sim_gen.py", "100", ".3"]
with open("./sim_gen.py 100 .3"):
exec(f.read())
finally:
sys.argv = _argv
Although really, unless the point of running this is to silently modify your own module's globals or the like, you (a) almost certainly don't really need exec, and (b) want to pass an explicit globals argument even if you do really need it.

Function not defined when Importing Maya Python Script

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

Trouble importing files in Python

I'm just finding out now that when importing a module, it seems to run through ALL the code, instead of just the one function that I want it to go through. I've been trying to find a way around this, but can't seem to get it. Here is what is happening.
#mainfile.py
from elsewhere import something_else
number = 0
def main():
print('What do you want to do? 1 - something else')
donow = input()
if donow == '1':
something_else()
while 1:
main()
#elsewhere.py
print('I dont know why this prints')
def something_else():
from mainfile import number
print('the variable number is',number)
Now, although this code KIND OF works the way I want it to, the first time when I initiate it, it will go to the main menu twice. For example: I start the program, press one, then it asks me what I want to do again. If I press one again, then it will print "the variable number is 0".
Once I get this working, I would like to be importing a lot of variables back and forth. The only issue is,if I add more import statements to "elsewhere.py" I think it will just initiate the program more and more. If I put "from mainfile import number" on line 1 of "elsewhere.py", I think this raises an error. Are there any workarounds to this? Can I make a different file? What if I made a class to store variables, if that is possible? I'm very new to programming, I would appreciate it if answers are easy to read for beginners. Thank you for the help.
As Jan notes, that's what import does. When you run import, it runs all of the code in the module. You might think: no it doesn't! What about the code inside something_else? That doesn't get run! Right, when the def statement is executed it creates a new function, but it doesn't run it. Basically, it saves the code for later.
The solution is that pretty much all interesting code should be in a function. There are a few cases which make sense to put at the top-level, but if in doubt, put it inside a function. In your particular case, you shouldn't be printing at the top level, if you need to print for some reason, put that into a function and call it when you need it. If you care when something happens, put it in a function.
On a second node, don't import your primary script in other scripts. I.e. if your mainfile.py directly, don't import that in other files. You can but it produces confusing results, and its really best to pretend that it doesn't work.
Don't try to import variables back and forth. Down that path lies only misery. You should only be importing things that don't change. Functions, classes, etc. In any other case, you'll have hard time making it do what you want.
If you want to move variables between places, you have other options:
Pass function arguments
Return values from a function
Use classes
I'll leave it is an exercise to the reader to learn how to do those things.
import executes imported code
import simply takes the Python source file and executes it. This is why it prints, because that instruction is in the code and with import all the instructions get exectued.
To prevent execution of part of imported package/module, you shall use the famous:
if __name__ == "__main__":
print("I do not print with `import`")
Note, that this behaviour is not new in Python 3, it works the same way in Python 2.x too.

How do I execute all the code inside a python file?

How do I execute all the code inside a python file so I can use def's in my current code? I have about 100 scripts that were all written like the script below.
For a simple example, I have a python file called:
D:/bt_test.py
His code looks like this:
def bt_test():
test = 2;
test += addFive(test)
return(test)
def addFive(test):
return(test+5)
Now, I want to from a completely new file, run bt_test()
I've tried doing this:
def openPyFile(script):
execfile(script)
openPyFile('D:/bt_test.py')
bt_test()
But this doesn't work.
I've tried doing this as well:
sys.path.append('D:/')
def openPyFile(script):
name = script.split('/')[-1].split('.')[0]
command = 'from ' + name + ' import *'
exec command
openPyFile('D:/bt_test.py')
bt_test()
Does anyone know why this isn't working?
Here's a link to a quicktime video that will help explain what's happening.
https://dl.dropbox.com/u/1612489/pythonHelp.mp4
You should put those files somewhere on your Python path, and then import them. That's what the import statement is for. BTW: the same directory as your main program is on the Python path, that could be a good place to put them.
# Find and execute bt_test.py, and make a module object of it.
import bt_test
# Use the bt_test function in the bt_test module.
bt_test.bt_test()
The reason that execfile doesn't work is because the functions inside bt_test are limited by the scope of the openPyFile function. One simple test would be to try to run bt_test() from inside openPyFile. Since openPyFile doesn't really do anything other than execfile you could get rid of it altogether, or you could alias execfile
openPyFile=execfile
Note putting the file in your python path and importing it is definitely your best bet -- I only post this answer here to hopefully point out why you're not seeing what you want to see.
In addition to Ned's answer, __import__() might be useful if you don't want the file names hardcoded.
http://docs.python.org/library/functions.html#__import__
Update based on the video.
I don't have access to Maya, but i can try and speculate.
cmds.button(l='print', c='bt_press()') is where the issue seems to lurk. bt_press() is passed as a string object, and whatever way the interpreter uses to resolve that identifier doesn't look in the right namespace.
1) Try passing bt_press() with the module prepended: cmds.button(l='print', c='bt_test.bt_press()')
2) See if you can bind c directly to the function object: cmds.button(l='print', c=bt_press)
Good luck.
>>> from bt_test import bt_test
>>> bt_test()

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