Raspberry Pi Python IDLE vs. __init__.py - python

I am using the tsl2561 python package on my RPi in order to interact with the tsl2561 light sensor. However, I am having a really weird occurrence that I cannot understand. Let me try to explain it the best I can.
If I open up IDLE and run
from tsl2561 import *
then when I try to run the TSL2561(debug=True) command it does not work and says TSL2561 is not defined.
However, when I open up the __init__.py file located in the tsl2561 folder (which contains only one line "from tsl2561 import *"), and run that file, it opens a new IDLE window upon where I can type
TSL2561(debug=True)
and it recognizes the function and allows me to see the light level. But, if I open IDLE again in a new window and run
from tsl2561 import *
TSL2561(debug=True)
I get the error saying TSL2561 is undefined.
So, my question is, if you understand it, why does the function work when I run the __init__ script which has the same line but not when I just open up IDLE and try to type the code myself?
Any help would be greatly appreciated because I need to be able to write a separate script without having to rely on always opening from the init file!
It is Python 3.4
Thanks,
Andrew

Related

Issue with executing php through cmd from python

I will try to be brief!
For whatever reason, I couldn't make the entirety of my program in python, so I had to outsource one specific task to php (a language I do not know very well). As the python program runs, it is supposed to trigger the php program to run, and then do a few things afterwards which is not a problem.
It seems to me that, to be able to run something through python, you need it to be able to run through cmd first, and then you can make python use cmd to run the program. I had a few issues there, because the programs are on different drives, and the php program references other files and locations in the same directory and in sub-directories to where it is, this means I couldn't execute in one line of cmd, but first had to change directory, to then execute the php program from the folder it's in. Because my command wasn't just one line, I made a batch file containing all the steps.
My current working method is to open up cmd, change directory in cmd to where the php file is, and then run the php file. I had to add php to the "Environment Variable Path" to be able to do this. Here is the batch file that currently works when run by me:
cd /d C:
cd C:\Users\UserMain\Desktop\php\colorextract
php (2).php
When I double click this bat file, from my E drive, it successfully executes the php program. But when I tell python to execute the batch file, that is where things go wrong.
Here is my python code, apologies for the name of the bat file:
import os
os.system('cmd /k "bitch.bat"')
The resultant cmd window then goes thru the steps of the batch file: 1) it changes to the right directory, 2) it is unable to execute the php file because:
'php' is not recognised as an internal or external command, operable program or batch file.
Now, this is the standard error you get if you were to try running a php program without having added php to the "Environment Variable Path", I know this because I went through that same thing. But if I manually open a cmd window, not administrative or anything, I can 1) successfully perform the steps outlined in batch file, and program runs, and 2) I can even run the bat file, and that also runs the program.
The cmd window opened by python does not seem to be able to reference the "Environment Variable Path", or it is for another reason somehow handicapped against being able to do all the things that a normal cmd widow can. How can this be fixed?
Thanks in advance to anyone who reads this!
Edit: I found that python had not detected the changes I made to the environment variables the day before, hence why python's cmd was giving the exact error that not having php in the environment variable gives. After I restarted my computer, my code worked. Thank you to #Gerhard and #Aaron Junker for making me think much harder about this issue.
so I found a command that can be run after importing os.
print(os.environ)
I ran this, and it told me that Python could not see that php had been added to the environment variables, well, more likely that python did not have the most up to date information regarding what was in the path variable(s).
Restarting my computer made the changes kick in, and now my original code works. Whilst I do feel very stupid, I'm just happy that this is resolved.
This seems to me like both instances use different environment variables.
Open
System Properties -> Advanced -> environment variables and look that PHP is in the PATH variable in user variables and in System variables.

Python Executable how to on Windows

I'm running windows
I've got a python script that works as expected when I run it from my interpreter (Anaconda, i think that's an interpreter...), but when I run it from my file manager by double clicking the script ("script.py") I see a quick black screen flash, but nothing else. I'm using the input() function, so that's not the issue.
When I try the same thing with a simple test script, which is just the print() function and the input function, the command line or terminal screen, whatever the black screen is called, displays my printed string and closes only after I press enter.
I believe my issue has to do with file paths and working directories, but I'm a noob and I don't know how to solve this. My script declares this variable:
inv_folder=r"C:\Users\domin\OneDrive\Desktop\Test Folder" #folder to look for completed recipe files
which I believe is an absolute filepath. I then loop through the files in that folder and open and read them
for filename in os.listdir(inv_folder):
Main goal is to send my script to someone else's computer, and allow them to run it simply by double clicking on the file. Trying to do that on my computer and failing
Doubleclicking the .py file in Windows will generally run the file. In your case, if all your script is doing is looking for a directory and looping through files in it, it is quite possible that the script is working correctly, but that it is closing immediately upon completing the script.
E.g. if you have the following python file hello.py with the single line of code.
print("hello world")
If you doubleclick hello.py, you will only see a black window flash for a second, as the program runs and exits.
To check whether your code is working correctly or not, you are best to navigate to that folder in your command prompt and run the program within the command prompt. E.g. typing "hello.py" in the right folder will then show the correct output in the console.
Try running it in the console first, seeing if the code is giving any errors, and then working from there. But the behaviour you are describing is basically standard Windows behaviour and not necessarily an error.
If you need to pause the window after running, please see the following StackOverflow question and answers about "Python Equivalent to System('PAUSE')"
Have you considered to compile it?
You can compile it easily with pyinstaller and this command:
C:\<path_to_python>\Scripts\pyinstaller.exe --onefile -n <your script name> <your script path>
Of course replace the <> with the relevant paths for you.

Running Python Scripts Outside of IDLE

1- i want someone to help with this part
https://automatetheboringstuff.com/appendixb/
about Running Python Scripts Outside of IDLE and sending command line args .
2- i converted my code to .exe by pyinstaller ; what's the difference between this and running it
as a script .
3-how scripts are done . i see experienced people says :"i made a script to do something for me " how is that done >?
*i'm a beginner so try to make answers simple as possible.
If you're wondering about command line arguments, look into the "argparse" library https://docs.python.org/3/library/argparse.html.
The difference in the .exe and the normal script is that that the .exe versions (conventionally) are able to be redistributed to other sytems that don't have python installed whilst still being able to run the script. If you're only making the script for yourself the only real benefit is that you dont have to enter your IDE (code editor) every time you want to run the code, however if it's still in development then you'd have to compile the code every time you made a modification if you're wanting to run the code as an executable, which is very impractical.
Your third part is very, very vague. Python can be very versatile and i recommend you continue looking at the automatetheboringstuff.com website if you're interested in making scripts that can complete repetitive activities (although i must strongly advise you against using scripts maliciously).

I'm new to Python and managed to crash IDLE after adding a line of code to my program

I'm working on a small game and, in the interest of full disclosure, I've learned some other languages before but this is only my second day learning Python.
What I was trying to do was simple enough: I was trying to generate a random integer between two integer values (e.g. random(a,b)). I looked around to see if there was an existing function that I could use, and I found information about a function called "randint". So I added a line of code to my program that looked something like:
value = randint(1,15)
I received an error that randint was undefined. So then I looked further and saw someone state that I needed to import the random library using the following line of code:
import random
The moment I refreshed (F5) IDLE crashed. So then I figured "welp, that was wrong" and I went to open IDLE and make the change. I was able to open IDLE, but I can't open the file. In fact, I can't open any of the (three) files that I've made. I opened the file in Notepad++ and removed the offending lines (both randint and import random), but IDLE still crashes whenever I try to open a file. I rebooted my laptop for lack of a better idea, but there was no change in behavior.
Details: Windows 7 x64 w/ all updates, Python 3.2.3.
...help? Also, what did I do? :-/
Received a solution from another forum:
"If you want to try diagnosing the problem, run the Python command line and then enter the line:
from idlelib import idle
That will launch idle, and you should get a traceback in the command prompt if something goes wrong."
When I did this it opened IDLE and produced an error (displayed in terminal) when I tried to open the file. Rather than crashing, I received a prompt (pop-up, not in terminal) to save the file. I found this odd because I had just opened it and hadn't made any changes. I let it save the file and then success! Now I can use IDLE to open any of my files again. Hope this helps someone else who encounters this issue :)
I'm not sure if this is helpful, but based on my experience, IDLE was never reliable enough for me. Practice using the command-line Python instead.
Go to the command prompt by running cmd
cd into your file's directory
type python yourfilename.py

Script works in IDLE, but .py-file doesn't work

I have a tkinter script, which runs just fine in IDLE. However, when I double click the .py-file from Windows Explorer, the console window flashes half a second and then it exits.
I was able to screenprint the console window. It says:
...etc.etc...
NameError: global name 'simpledialog' is not defined
simpledialog is a module in tkinter which I use in my script. As I do from tkinter import *, there is no need to explicitly write tkinter.simpledialog.
It works in IDLE, why not as .py?
IDLE uses Tkinter as its graphical environment. It is possible that your code is relying on a side effect of an import by IDLE itself. This is especially true if you use IDLE without a subprocess.
The simpledialog module does not import when using from tkinter import *.
Try adding this to your code:
import tkinter.simpledialog as simpledialog
Have you updated your PATH environment variable so that your Python executable is found? You can find more information on how to do here - Using Python on Windows
But you basically need to make sure that the folder containing python.exe (e.g. C:\Python32) is displayed when you type the following command from a prompt:
echo %PATH%
I had exactly the same problem with one of my scripts utilizing Tkinter.
Adding call to mainloop() fixed the issue.
See this tutorial for an example: [http://sebsauvage.net/python/gui/#import1
In my case, in the init function I have
def __init__(self,Width=400, Height=400):
# Create GUI window ------------------------------
win = Tk()
...
in the end of init I added:
win.mainloop()
Now it works by just running the file.
Hope this helps
Similar trouble for me just now, in my first week with python. But I dimly remembered a similar problem with a simple early test script and thought the trouble then was # comments.
So I tried that with my Tkinter infused .py script. It ran fine in IDLE as you say, then only flashed when clicked in windows. But there were a couple # commented lines at the top of file.
I took them all out and it now runs no sweat directly in windows. Have a look .. for #.
Sorry, can't seem to delete this post. Now the files work #comments included. Don't know what's up with that. ..
I found that changing the executable py file to a file.pyw fixed the problem. This tells python to execute it using the pythonw.exe which runs the script without the terminal/console in the background.
Not sure why this works, perhaps some screwed up environment variables from a previous python installation.
Changing the file's extension to pyw instead of py might solve the problem

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