IDLE is Python’s Integrated Development and Learning Environment and is an alternative to the command line. As the name may imply, IDLE is very useful for developing new code or learning python. On Windows this comes with the Python interpreter, but in other operating systems you may need to install it through your package manager.
The main purposes of IDLE are:
In IDLE, hit
run Python Shell to launch an interpreter. Using IDLE can be a better learning experience for new users because code is interpreted as the user writes.
Note that there are lots of alternatives, see for example this discussion or this list.
If you're on Windows, the default command is
python. If you receive a
"'python' is not recognized" error, the most likely cause is that Python's location is not in your system's
PATH environment variable. This can be accessed by right-clicking on 'My Computer' and selecting 'Properties' or by navigating to 'System' through 'Control Panel'. Click on 'Advanced system settings' and then 'Environment Variables...'. Edit the
PATH variable to include the directory of your Python installation, as well as the Script folder (usually
C:\Python27;C:\Python27\Scripts). This requires administrative privileges and may require a restart.
When using multiple versions of Python on the same machine, a possible solution is to rename one of the
python.exe files. For example, naming one version
python27.exe would cause
python27 to become the Python command for that version.
You can also use the Python Launcher for Windows, which is available through the installer and comes by default. It allows you to select the version of Python to run by using
py -[x.y] instead of
python[x.y]. You can use the latest version of Python 2 by running scripts with
py -2 and the latest version of Python 3 by running scripts with
This section assumes that the location of the
python executable has been added to the
PATH environment variable.
If you're on Debian/Ubuntu/MacOS, open the terminal and type
python for Python 2.x or
python3 for Python 3.x.
which python to see which Python interpreter will be used.
The default Python on Arch Linux (and descendants) is Python 3, so use
python3 for Python 3.x and
python2 for Python 2.x.
Python 3 is sometimes bound to
python instead of
python3. To use Python 2 on these systems where it is installed, you can use