I'm a beginner in Python with no prior programming experience, so bear with me here.
I installed Python, started playing with it (typing variables, playing with math operations) in the Shell window and everything is fine. I open a New Window and started writing a simple script. Something like this:
print (1+1)
I press Run Module, and I am asked to name and save the script first. I do so by calling it firstscript.py, and save it to my desktop.
Now I press Run Module, and in the shell window 2 is printed on the screen. Everything is fine. I close Python, and open it up again. Now in the shell window, I type firstscript.py and I get the red message NameError: name 'firstscript' is not defined.
I can run my program only if I open the script file on my desktop and press Run Module from there, but if I try to start it up directly in IDLE Shell by typing its name, I get the error message.
What did I do wrong? Thank you.
Good to see that you are starting with python.
Firstly, you can run the file directly using 'Run Module' only when you have the file open. Once you save the file and quit, you are out of the file editor and back to the terminal.
Simply typing in firstscripty.py will not work as it does not recognize the command.
To run the file from the terminal, use the below code:
python [locationOfFile\]firstscript.py
You can check out this detailed explanation: https://realpython.com/python-idle/#how-to-work-with-python-files
The problem here is the Shell doesnt know that your firstscript.py is sitting on the desktop
The simplest way i suggest using cmd with:
python C:\Users\{your user}\Desktop\firstscript.py
Related
My terminal is running python 2 so when I run my python file the program fails.
So basically I am new to programming and trying to create a small python script to help me auto create folders. I also want to give the script to colleges so that they can use it on their systems too.
I know that I can run my file in terminal by using "python3 myfile.py" and it will work, but that's too much off a mission to do for my colleges and as my colleges are not familiar with code or terminal for that matter, I wanted to create an executable file so that they just click to open type a few answers to the promoted question and boom folders created.
This is where I run into a problem, I have "#!/usr/bin/env python3" at the top of my file but when I run the script IDLE opens up and it just shows the code I have written but doesn't seem to run the actual script I wrote. Am I doing something wrong?
I also then though perhaps I could just use the terminal to run the file as it is now executable, so I go into terminal and enter "myfile.py" and the program runs but in python 2 so my script fails as it is in python3. So another question would be is there a way to code into my python file, when running this file make sure you use python3? as I would want this to work on all colleges system without them having to write out anything in terminal?
Sorry for the long explanation but any advice would be greatly appreciated.
Thank you in advance
When you are on windows you can just create a .bat file where you write: python3 myfile.py in it.
Both files have to be in the same directory.
If you want to have a .exe you can also use py2exe.
You could also try just #!/usr/bin/python3 without env.
More here.
I'm trying out some data science tutorials with python and can't get print to, well, print! when I run a .py in windows command shell or powershell. Print does work when I use the interpreter, but I have to type it in line by line (I'm not seeing how to run a .py as a file in the interpreter). I'm attaching snips of the file, and a snip of me running in the interpreter. I tried to attach snips of what happens when I run in command shell and powershell, but apparently I need at least 10 reputation points before I can post more than 2 links. Admittedly, those snips weren't interesting; there is no error and nothing printed. It just runs and returns to the prompt.
Also, as a test, I saved a .py file that simply does print ("Hello") and it does print correctly in windows command prompt and powershell.
Thanks in advance for any help!
Casie
PY script
Snip From Python Shell
Is that image from the IDLE console? To run the script you are editing, use menu Run > Run Module, or F5. Every python GUIs has an equivalent feature.
To run an arbitrary script from inside the commandline interpreter, say mywork.py: As long as it's in the working directory that you were in when you started the interpreter, you run it (once) by typing import mywork. (As you can see, its name must be a python identifier.)
Edit: You'd get to the bottom of this a lot quicker if you'd put print("Hello, world") in a script by itself and run it. From over here it looks like it would print just fine, proving there's nothing wrong with your python interpreter.
Your script has a bug, though: As soon as you enter the function random_kid(), you leave it again since you return a value on the first line. All those print statements are never executed. Why you think it works differently with %run I can't say, but for sure this function cannot print any output.
This question already has answers here:
How do I run a Python program in the Command Prompt in Windows 7?
(24 answers)
Closed 7 years ago.
So I'm an extreme beginner to programming, just starting the Python class on Coursera. Using Python 2.7.10
Anyway, I made a simple print statement script in Notepad++
print "Hello World"
and saved as a python file on my desktop
newprog.py
However when I try to run it a cmd window appears and disappears and I'm not quite sure whats wrong.
The other question that this was linked as a duplicate to is about accessing python through the command prompt, which I don't have a problem with. From answers given it is now apparent to me that my dilemma was due to an erroneous belief that the interpreter would remain open after running whatever script I wrote.
Sounds like your program simply opened, ran and exited. So nothing was wrong, it just all happened a bit quick for you to see it.
You should run it from a command prompt or get an IDE like Pycharm, which will allow you to both write and run your script in one program.
To run from command prompt, use either Windows Key + R and type 'cmd' or click start and type 'cmd' into search box. Then you can drag your script to the command prompt window and press Enter to run it.
If you wanted to run it by double click, you'd need something to stop it from finishing until you'd read the message. To achieve this you can use the raw_input function, which waits for user input.
So your script would then look like
print "Hello World"
raw_input("Press Enter to exit")
Then you could double click and press enter when you are ready to exit.
Go to the command prompt window
python
then type in
execfile('path to newfile.py here')
Your file will now be executed
I'm running python 3.4.3. But it should be the same, I hope.
Go go "..\PythonXX\Lib\idlelib" and look for idle.pyw NOT idle.py and using the you're able to execute simple one line commands like the one you have up there.
From that you can also create a new file and do more complicated stuff.
If you create a shortcut to your desktop, you'll be able to access it easier.
Let me know if it helps, or at least correct path.
Your script is probably working and then finishing, the result is shown but not for long. I recommend opening the console and running your script from there, or you could use a simple batch file to run python scripts and then wait for a key press.
To open the console you can use the Windows key along the R key, Win-R (to run a new process) and write cmd, or you look for cmd in your Window's start menu.
With the console opened, you must locate the path where your script is, you can use the cd (Change Directory) to get there, for example:
cd C:\Users\your_name\Desktop
and then write:
python newprog.py
to run your script.
Another option is to use this simple batch file (save it as python34.bat or similar, but the extension must be .bat, put it wherever you like):
#ECHO OFF
C:\Python34\python.exe %*
pause
#ECHO ON
And then use that to run your scripts by right clicking a python script file, open with (run with) and use this batch script as default (if you want). Also, if you have another version of Python, or is installed elsewhere, you must change the "C:\Python34\" part.
This is a computer we're talking about here. It might take you triple the time it takes a computer to multiple two numbers for example. With this notion in mind, the computer quickly prints then exits.
raw_input() # at the end of script wait for user to supply input, delaying script exit
I am a complete noob when it comes to programming. I just downloaded python and I will be using Notepad ++. I have saved a file to my desktop and the file name is test and changed the extension from .txt to .py
So when I go to Notepad ++ and create a program and save it, I go to the cmd prompt making sure I am in my desktop directory and type the following
python test.py
and it tells me that python is not recognized. Any help to fix this problem would be greatly appreciated.
First thing python is indent oriented programing language and it comes with its default editor called IDLE. So if you use notepad++ instead of IDLE it might gives you a syntax error. Second thing for executing python file from command prompt,you need to setup environment variable.Please see below link for setting up environment variable.
https://docs.python.org/2/using/windows.html
You can directly run your program in IDLE without using command prompt. So i would suggest you to use pythons built in editor (IDLE)
This obviously an extremely novice question, but I've installed Python 2.7 and started reading the manual. However I looked and looked, and couldn't understand how to start programming a file rather than writing in interactive mode. One book that was online suggested quit(), which surprise -- quit the program.
Should coding be done in a different program? I'm using IDLE (Python GUI). Can coding not be done within that program?
Yes, coding should be done in a different program. The interactive shell is very useful but it's not an editor.
You write Python code line by line (as you would on Python interactive mode) in a text editor such as vim, emacs etc...
Then you run these line by line code using the Python interpreter by giving it the name of your script.
$ python myscript.py
I like to use a different directory for each project. Suppose I decide to use W:/mytest as my directory. First I create the directory.
Then I start Idle. I type the following:
import os
os.chdir("W:/mytest")
This makes W:/mytest the current directory for Idle.
import sys
sys.path.append(".")
This changes the path so that when I "import", it will look in the current directory.
Next I do File / New Window to open an editor window, and in that new window I select File / Save As. It starts in the Python home directory so I have to navigate to W:/mytest. I save this (empty) file as "test1.py".
I type this into my test1.py file and save it again:
""" test1.py is my test
"""
print ("This is test1.")
class Test1:
def __init__(self):
print ("Constructed")
This is a contrived example that can be run as a script or imported as a module.
So I have two windows now; an editor window and the Idle "Python Shell". I can do this in the Python Shell:
>>> execfile("test1.py")
This is test1.
>>> import test1
This is test1
>>> tt = test1.Test1()
Constructed
Push new to start making your own script file. Then when you are ready to test click run and then you can watch the results in the interactive mode, and even try new things as if you were adding code to the end of your script file, its a very useful app for debugging, testing and trying new things.
Also in the options you can change the way python opens your scripts when you click edit from windows, you can set it so that it opens the interactive shell or just the editor.
use new window tool in the file icon,in the python idle itself to write a program
To start coding in a file, just open a new file and start typing.