IDLE — Python Interpreter

IDLE (Integrated Development and Learning Environment) is the default IDE bundled with every Python installation.

Two modes of working in IDLE

1. Interactive Mode (Shell) — statements are typed at the >>> prompt and executed immediately, one at a time. Ideal for testing small snippets.

>>> 2 + 3
5
>>> print("Hello, Python")
Hello, Python

1. Script Mode (Editor) — a complete program is written in a .py file and executed as a whole using Run → Run Module (F5).

# hello.py
name = input("Enter your name: ")
print("Welcome,", name)

Run from the terminal:

python hello.py

The Python Interpreter

The interpreter reads Python source code and executes it directly — statement by statement — without needing a separate compilation step (though internally it compiles to bytecode first).

IDLE Features

• Syntax highlighting — color-coded keywords, strings, comments.
• Auto-completion — suggests function/variable names.
• Auto-indentation — automatically indents after :.
• Integrated debugger — step through code, inspect variables.
• Call tips — shows function signatures while typing.

Checking installation

python --version
python3 --version

Getting help inside IDLE

>>> help(print)
>>> help(str)