Running Python
Run Python code from a file or interactively in the REPL.
Syntax
python hello.pyThere are two main ways to run Python code.
1. Run a script file
Save your code in a file ending in .py, then run it from the terminal with python filename.py.
2. The interactive REPL
Type python with no filename to open the REPL (Read-Eval-Print Loop). You type one line, press Enter, and see the result instantly. It is perfect for quick experiments. Type exit() to leave.
Example
# A file called hello.py containing:
name = 'Ada'
print('Hello,', name)
# Run it with: python hello.py
# Output:
# Hello, AdaWhen to use it
- A developer runs a data processing script from the terminal each morning to generate reports.
- A learner opens the REPL to quickly test how a string method behaves.
- A CI pipeline executes a Python test file automatically on every code push.
More examples
Run a script file
Shows the standard way to execute a Python source file from the terminal.
# Save this as hello.py:
# name = 'Ada'
# print('Hello,', name)
python hello.py
# Output: Hello, AdaUse the REPL interactively
Demonstrates typing expressions into the REPL and seeing results without print().
# Inside the Python REPL (started with: python3)
>>> x = 7
>>> x * 6
42
>>> 'hello'.upper()
'HELLO'
>>> exit()Run one-liner from terminal
Uses the -c flag to run a short Python expression directly in the shell.
python3 -c "print('Hello from the command line')"
# Output:
# Hello from the command line
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