2. Using the Python Interpreter
2.1. Invoking the Interpreter:-
The Python interpreter is usually installed as /usr/local/bin/python3.11 on those
machines where it is available; putting /usr/local/bin in your Unix shell’s search path
makes it possible to start it by typing the command:
python3.11
to the shell. 1 Since the choice of the directory where the interpreter lives is an
installation option, other places are possible; check with your local Python guru or
system administrator. (E.g., /usr/local/python is a popular alternative location.)
On Windows machines where you have installed Python from the Microsoft Store,
the python3.11 command will be available. If you have the py.exe launcher installed,
you can use the py command. See Excursus: Setting environment variables for other
ways to launch Python.
Typing an end-of-file character (Control-D on Unix, Control-Z on Windows) at the
primary prompt causes the interpreter to exit with a zero exit status. If that doesn’t
work, you can exit the interpreter by typing the following command: quit().
The interpreter’s line-editing features include interactive editing, history substitution
and code completion on systems that support the GNU Readline library. Perhaps the
quickest check to see whether command line editing is supported is typing Control-
P to the first Python prompt you get. If it beeps, you have command line editing; see
Appendix Interactive Input Editing and History Substitution for an introduction to the
keys. If nothing appears to happen, or if ^P is echoed, command line editing isn’t
available; you’ll only be able to use backspace to remove characters from the current
line.
The interpreter operates somewhat like the Unix shell: when called with standard
input connected to a tty device, it reads and executes commands interactively; when
2.1. Invoking the Interpreter:-
The Python interpreter is usually installed as /usr/local/bin/python3.11 on those
machines where it is available; putting /usr/local/bin in your Unix shell’s search path
makes it possible to start it by typing the command:
python3.11
to the shell. 1 Since the choice of the directory where the interpreter lives is an
installation option, other places are possible; check with your local Python guru or
system administrator. (E.g., /usr/local/python is a popular alternative location.)
On Windows machines where you have installed Python from the Microsoft Store,
the python3.11 command will be available. If you have the py.exe launcher installed,
you can use the py command. See Excursus: Setting environment variables for other
ways to launch Python.
Typing an end-of-file character (Control-D on Unix, Control-Z on Windows) at the
primary prompt causes the interpreter to exit with a zero exit status. If that doesn’t
work, you can exit the interpreter by typing the following command: quit().
The interpreter’s line-editing features include interactive editing, history substitution
and code completion on systems that support the GNU Readline library. Perhaps the
quickest check to see whether command line editing is supported is typing Control-
P to the first Python prompt you get. If it beeps, you have command line editing; see
Appendix Interactive Input Editing and History Substitution for an introduction to the
keys. If nothing appears to happen, or if ^P is echoed, command line editing isn’t
available; you’ll only be able to use backspace to remove characters from the current
line.
The interpreter operates somewhat like the Unix shell: when called with standard
input connected to a tty device, it reads and executes commands interactively; when
