问题
I am using python 3.5.2 version in windows 7 and tried using python3 app.py. I am getting this error message
'python3' is not recognized as an internal or external command,
operable program or batch file.
any specific cause about why python3 command is not working? I also verified that the PATH is added to environment variables.
回答1:
There is no python3.exe file, that is why it fails.
Try:
py
instead.
py is just a launcher for python.exe. If you have more than one python versions installed on your machine (2.x, 3.x) you can specify what version of python to launch by
py -2 or py -3
回答2:
Python3.exe is not defined in windows
Specify the path for required version of python when you need to used it by creating virtual environment for your project
Python 3
virtualenv --python=C:\PATH_TO_PYTHON\python.exe environment
Python2
virtualenv --python=C:\PATH_TO_PYTHON\python.exe environment
then activate the environment using
.\environment\Scripts\activate.ps1
回答3:
If python2 is not installed on your computer, you can try with just python instead of python3
回答4:
You can also try this: Go to the path where Python is installed in your system. For me it was something like C:\Users\\Local Settings\Application Data\Programs\Python\Python37 In this folder, you'll find a python executable. Just create a duplicate and rename it to python3. Works every time.
回答5:
For Python 27
virtualenv -p C:\Python27\python.exe django_concurrent_env
For Pyton36
virtualenv -p C:\Python36\python.exe django_concurrent_env
回答6:
Enter the command to start up the server in that directory: py -3.7 -m http.server
回答7:
In my case I have a git hook on commit, specified by admin. So it was not very convenient for me to change the script (with python3 calls).
And the simplest workaround was just to copy python.exe to python3.exe.
Now I could launch both python and python3.
回答8:
Yes, I think for Windows users you need to change all the python3 calls to python to solve your original error. This change will run the Python version set in your current environment. If you need to keep this call as it is (aka python3) because you are working in cross-platform or for any other reason, then a work around is to create a soft link. To create it, go to the folder that contains the Python executable and create the link. For example, this worked in my case in Windows 10 using mklink:
cd C:\Python3
mklink python3.exe python.exe
Use a (soft) symbolic link in Linux:
cd /usr/bin/python3
ln -s python.exe python3.exe
来源：https://stackoverflow.com/questions/39910730/python3-is-not-recognized-as-an-internal-or-external-command-operable-program