Whenever I do a project for computer science, I have to make sure all of my files are located in the same folder, or I'll have errors. If I want to use a file from somewhere else, I have to insert it into the path. I do these things but don't fully understand what is happening or why. Why is the path changed in the runtime environment?
When you run a python script you are executing it in the current working directory /home/user/python.py for example. That means this script since it lives in /home/user has access to everything in that path. However you should be able to access any other directory from here as long as the permissions are setup right. You would do that by using relative paths. so for example /home/user/python.py could access a file that is /home/example/file.txt by giving it the path ../example/file.txt from the python project.
Have you tried adding the path using sys.path.append? If you don't want to do that every time then you can set (Windows) %PYTHONPATH% to include your custom path. That's what I do for my include folder.
I know that the directory can be automatically changed to that of the current script if we press F5.
But is there a way to automatically do so when I run the codes in interactive mode, or when I open a script? Currently I need to os.chdir() to the current working directory.
Thanks.
You can add the following lines to your script:
import os
os.chdir(os.path.dirname(__file__))
__file__ will return the path of the script, and we can use os.path.dirname to find which directory it is located in. Then just use os.chdir to change to that directory.
I have Python 3.7 on my path (I can execute .py scripts when I am in that local directory in cmd)
I also have a folder of scripts on my path (I can open them from any local directory in cmd i.e. by typing "script.py")
However, I cannot execute these scripts from any local directory explicitly using python, i.e. "python script.py"
Any ideas why this is the case? Thanks
Edit:
The desired folder "scripts" is set in PYTHONPATH variable, and checking within python I see
import sys
sys.path
['', 'C:\Users\benma\Desktop\scripts',...
I can import a file from scripts into python already running, but not execute it directly
Python doesn't search PATH to look for your scripts. You can run the script directly because the shell is searching PATH looking for something that matches.
PYTHONPATH won't help when executing from the shell. It is only used by Python when importing modules:
Augment the default search path for module files.
I don't think you're going to get exactly what you're after. The closest is probably executable modules.
Saying I create a.py under path/to/somewhere/. And later in the IDE(pycharm), I refactor it to path/to/another_place/.
But when I run a.py later, os.getcwd() show its working directory is still in path/to/somewhere. ( os.listdir('.') also show it is in original place.)
The following picture is what I meet , makeimg.py is originally in learn_function
I am new to python and I don't understand how a file/modoule locate itself.
Am I do something wrong? or it is a bug?
os.getcwd() returns the current working directory, it may/may not be the directory in which the your script exists, its the directory from which the script was run. Most probably in your PyCharm Run/Debug configuration you have set the Working directory to path/to/somewhere .
From run/debug configuration doc page for pycharm -
Working directory - Specify a directory to be used by the running task.
When a default run/debug configuration is created by the keyboard shortcut Ctrl+Shift+F10 , or by choosing Run on the context menu of a script, the working directory is the one that contains the executable script. This directory may differ from the project directory.
Ideally your code should not depend on the current working directory , since you can run a python file from anywhere using absolute path to the python file.
Instead if you want the path in which the script resides, use __file__ to get that path in the script.
Example -
print(__file__)
This should print the script's path (as given in sys.argv[0]).
I'm new and I have no idea where the default directory for the open() function is.
For example open('whereisthisdirectory.txt','r')
Can someone advise me? I've tried googling it (and looking on stackoverflow) and even putting a random txt file in so many folders but I still can't figure it out. Since I'm beginning, I want to learn immediately rather than type "c:/directory/whatevevr.txt" every time I want to open a file. Thanks!
Ps my python directory has been installed to C:\Python32 and I'm using 3.2
os.getcwd()
Shows the current working directory, that's what open uses for for relative paths.
You can change it with os.chdir.
If you working on Windows OS first type
import os
then type
os.getcwd()
and it should print the current working directory.
The answer is not python-specific. As with programs written in any other language, the default directory is whatever your operating system considers the current working directory. If you start your program from a command prompt window, the CWD will be whatever directory you were in when you ran the program. If you start it from a Windows menu or desktop icon, the CWD is usually defined alongside the program's path when creating the icon, or else falls back to some directory that Windows uses in the absence of that information.
In any case, your program can query the current working directory by calling os.getcwd().
The default location is the CWD (Current Working Directory), so if you have your Python script in c:\directory and run it from there, if you call open() it will attempt to open the file specified in that location.
First, you must import:
import os
Then to print the current working directory:
os.getcwd()
If you want to change the current working directory:
os.chdir('your_complete_required_path')
create the .txt file in the directory where u have kept .py file(CWD) and run the .py file.
The open() function for file always creates files in the current working directory. The best way to find out your current working directory is to find three lines of small code:
import os
current_working_directory = os.getcwd()
print(current_working_directory)
Run this above code and you will get your current working directory where open() function creates a new file. Good Luck!
If you’re running your script through an interpreter (i.e pycharm, VSCode etc) your Python file will be saved, most likely, in my documents (at least in VSCode, in my personal experience) unless you manually save it to a directory of your choosing before you run it. Once it is saved, the interpreter will then use that as you current directory so any saves your Python script will create will also automatically go there unless you state otherwise.
it depends on how you run it from the terminal
like this, it is going to look in your home directory
C:\Users\name>python path\file.py
and like this, it is going to look next to your file
C:\Users\name>cd path
C:\Users\name\path>python file.py