I just downloaded Python 3.2 to Mac OS 10.6 environment. I'm new to programming and am trying to run my first stand-alone .py file, but I keep getting an error message saying "no such directory or file." The name of the file is "script1.py" and I saved it to /Users/billp/Documents. When I open the Terminal to run the file I type:
python script1.py
I've also tried adding this line to the beginning of the script:
#!/usr/local/bin/python
As well as this one:
#!/usr/bin/env python
Yet, I keep getting the same error message. Any help would be greatly appreciated.
Make sure you are in the right working directory after opening terminal. Type
cd /Users/billp/Documents/
(use tab to autocomplete)
then
python ./script1.py
This way you are launching python executable and passing it path to your file as the first argument. The shebang #! line you mentioned allows you to launch your script directly, like this: ./script1.py, but you need to mark the file as executable chmod +x script1.py and provide path to interpreter (python) after the shebang. #!/usr/bin/env python references your default python installation.
The ./ stands for current directory. By default when you type script1.py your shell (which is the thing that you type commands into, through the terminal) would look for executable file in special folders listed in PATH env variable. script1.py is not usually there, so you would see -bash: script1.py: command not found. python, on the other hand is on the PATH so it should work.
Maybe you forgot to make the file executable? Try this at the command prompt:
$ chmod +x script1.py
I prefer to start my Python scripts in a Mac with these lines (assuming of course that you're saving the file in UTF-8 encoding:
#!/usr/bin/env python
#coding=utf-8
Also, make sure that the pythoncommand is available in the path. If everything is set up correctly, it won't be necessary to type python first, and you can run the script directly by typing ./script1.py in the directory where it is located.
One final thing, for running a piece of code when executing the script from the command line (as opposed to simply loading the definitions in the file), write this at the end:
if __name__ == '__main__':
# the code you want to call
Are your python binaries here?
/Library/Frameworks/Python.framework/Versions/3.2/bin/python
It's worth pointing out, as long as the file is in your current directory it's automatically available. Otherwise, anything files will have to be referenced absolutely using the full path information.
So the following examples are calling the same file:
Explicit (absolute path)
python /Users/billp/Documents/script1.py
python /Users/billp/Documents/script2.py
python /Users/billp/Documents/script3.py
Implicit (relative path)
cd /Users/billp/Documents
python script1.py
python script2.py
python script3.py
As long as you're working with files in the same directory (commonly known as your working directory), you may always safely use relative paths. If the files are anywhere else, you must always specify an absolute path.
Related
What's the difference between running python file as a module executed as a script vs just running the python file? In particular, I'm wondering what the difference is between running
python -m filename vs
python filename.py
I'm reading the documentation here: https://docs.python.org/3.6/using/cmdline.html but it's not entirely clear to me.
In particular, I notice that when I'm running a file I wrote that imports other modules I've written, it works when I run python -m filename but when I run python filename.py it says it can't find the module I've written. Why is this? Is this something to do with the path?
I am not a python guy but I read something in the link you have provided that may provide some explanation.
If this option is given, the first element of sys.argv will be the
full path to the module file (while the module file is being located,
the first element will be set to "-m"). As with the -c option, the
current directory will be added to the start of sys.path.
I guess what that means is that the directory you are running python -m filename is added to the system path. The sys.path (or system path) is basically a list of paths (folders) that python will try search for the file you are trying to import. I am assuming the files you are looking for in your import is in the same folder you run python -m filename. Running python without the -m does not modify the sys.path list.
You can read more on this here https://docs.python.org/3.6/library/sys.html#sys.path
Hope this is what you want.
I have a Python script that I would like to be able to execute from no matter where. Either in Linux or in Windows, but in this case preferably in Windows. Putting the path to the script into PATH under Windows did not work, so from some directory calling python my_script.py results in the message that there is no such file in this directory. So, is this somehow possible?
You can try creating an alias as such:
Linux
Create a .bash_aliases file on your home folder
Add an alias such as alias pscript='python /home/pythonscript.py'
Log out and back in or do a source .bash_aliases
Windows
Run doskey pscript=python C:\script.py. Read more here
The PATH is used to search for executables, and this doesn't include in windows script files.
A workaround is to convert the script to a batch file, see here
how to simply have the script act also as a batch file
For the operating system to run your script, it needs to find it (the PATH variable), recognize that it is executable and know which program should execute it. You seem to have the PATH part handled, so now for the other two.
On unixy systems you need to make the script executable. To set the user-executable bit, do chmod u+x myscript.py. Then you need to tell the system which program should run it. Typically you use the "shebang" as the very first line in the file:
#!/usr/bin/env python3
The system will search the path for a program called "python3" (use "python" for python 2 scripts) and use that executable to run the script.
On Windows, you need to associate the file extension (.py) with the python exeuctable. That's usually done for you when python is installed. If not, you can dig into ftype, assoc and pathext here.
Windows doesn't care about the shebang (unless you are running cygwin, then see unixy systems above) so the same script can live in both worlds.
Once the script is executable, you call it directly instead of executing python and giving the file as the script name. Its just
myscript.py
I have Python 2.7 installed at C:\Python27 and I have added the path C:\Python27\; to the environment variables and .py: to PATHEXT. I am able to launch Python.
I downloaded a folder google-python-exercises to my desktop, which contains a script hello.py.
Following the advice in the Google Developers course, I try to run the script by using python hello.py at the command prompt.
When I attempt this, I get the message: python: can't open file 'hello.py: [Errno 2] No such file or directory. What is wrong, and how am I supposed to fix it? I found that I can solve the problem by running cmd from the folder, but this seems like a temporary solution.
Python cannot access the files in the subdirectory unless a path to it provided. You can access files in any directory by providing the path. python C:\Python27\Projects\hello.py
I resolved this problem by navigating to C:\Python27\Scripts folder and then run file.py file instead of C:\Python27 folder
Options include:
Run the command from the folder where hello.py is located (this way, hello.py is already a relative path to the file). This is the solution that OP found.
Give a proper path to the hello.py file - either absolute (e.g. C:/Users/me/Desktop/google-python-exercises/hello.py) or relative (for example, google-python-exercises/hello.py, if the current working directory is the desktop).
Add a path to the folder (C:/Users/me/Desktop/google-python-exercises) to the PYTHONPATH environment variable, and run the code as a module (python -m hello).
In all cases, a path is being given directly - Python will not "search" for the file.
From your question, you are running python2.7 and Cygwin.
Python should be installed for windows, which from your question it seems it is. If "which python" prints out /usr/bin/python , then from the bash prompt you are running the cygwin version.
Set the Python Environmental variables appropriately
, for instance in my case:
PY_HOME=C:\opt\Python27
PYTHONPATH=C:\opt\Python27;c:\opt\Python27\Lib
In that case run cygwin setup and uninstall everything python.
After that run "which pydoc", if it shows
/usr/bin/pydoc
Replace /usr/bin/pydoc
with
#! /bin/bash
/cygdrive/c/WINDOWS/system32/cmd /c %PYTHONHOME%\Scripts\\pydoc.bat
Then add this to $PY_HOME/Scripts/pydoc.bat
rem wrapper for pydoc on Win32
#python c:\opt\Python27\Lib\pydoc.py %*
Now when you type in the cygwin bash prompt you should see:
$ pydoc
pydoc - the Python documentation tool
pydoc.py <name> ...
Show text documentation on something. <name>
may be the name of a Python keyword, topic,
function, module, or package, or a dotted
reference to a class or function within a
module or module in a package.
...
Try uninstalling Python and then install it again, but this time make sure that the option Add Python to Path is marked as checked during the installation process.
Hi everyone I'm trying to get Python configured on an OS X laptop and I'm having some trouble. I'm both new to Python and am very unfamiliar with the UNIX terminal. What I'd like to be able to do is to have a directory in my documents folder that would contain python modules and be able to run them from the command line. Currently I have a Python Directory and a chaos.py module inside of it. The full path is /Users/Ben/Documents/Python/chaos.py.
So I followed the steps here and here. I can see that the site-packages for Python 3.4 is in a few spots but I chose this one: '/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages' to place the .pth file.
I created a file named Ben.pth in this location with the contents: /Users/Ben/Documents/Python/
Now from my (very limited) understanding that should be all I would need to do for Python to start looking right? So I try to run python3 chaos.py in terminal and I get an error:
/Library/Frameworks/Python.framework/Versions/3.4/Resources/Python.app/Contents/MacOS/Python: can't open file 'chaos.py': [Errno 2] No such file or directory
I'll also try opening IDLE clicking File->Open Module... and try to open it from there and I'll recieve a "module not found" box.
I'm completely stumped, I'm not sure if its a syntax error that I made somewhere (again I don't really know what I'm doing with the UNIX commands) or if I'm just way out in right field. If anyone could help me out, I would greatly appreciate it! Thanks!
Forget the .pth stuff for now, that's not something you'd normally do. In a unix-ish environment, the typical way you'd run a script would be to change directory:
cd /Users/Ben/Documents/Python/
and then run the script:
python chaos.py
Another way to do it would be to run the script with an absolute path; you can do this no matter your current working directory:
python /Users/Ben/Documents/Python/chaos.py
Finally, if you've written a utility script you want to be run from anywhere without typing that absolute path all the time, you can do something a little fancier...
Add a 'shebang' line as the first line of your script. It'll go like this:
#!/usr/bin/env python
Get into the directory where your script lives:
cd /Users/Ben/Documents/Python/
Make the script executable:
chmod +x chaos.py
Put a link to the script in a directory on your path... /usr/local/bin/ could be a good choice:
ln -s /Users/Ben/Documents/Python/chaos.py /usr/local/bin/chaos.py
Now you can type chaos.py anywhere on your system and it'll run.
how can i run my program using test files on my desktop without typing in the specific pathname. I just want to be able to type the file name and continue on with my program. Since i want to be able to send it to a friend and not needing for him to change the path rather just read the exact same file that he has on his desktop.
f = open(os.path.join(os.environ['USERPROFILE'], 'DESKTOP', my_filename))
If you are on Unix/Mac you can add a shebang at the top of your script and set it as executable. Usually you'd do:
#!/usr/bin/env python
And then to make it executable, from a terminal use chmod:
chmod +x script.py
Now you can run the script (if you are in the same directory) like:
./script.py
If you are on Windows you'll want to add the Python executable to your %PATH% enviromental variable, then you can run your script with python script.py. They talk about this in more depth in the Python documentation: http://docs.python.org/using/windows.html
If you place your Python script in the same directory as the files your script is going to open, then you don't need to specify any paths. Be sure to allow the Python installer to "Register Extensions", so Python is called when you double-click on a Python script.
You can tell your friend to make *.py files to be executed by the interpreter. Change it from Explorer:Tools:Folder Options:File Types.