Quick Python Syntax Checks from the Command Line

1 min read

Today I learned a handy trick to check Python syntax without running your code. Perfect for catching errors early.

From the Command Line

You can run:

python3 -m py_compile src/app/analysis.py && \
  echo "👍 Syntax is valid – no errors found"

Or for another file:

python3 -m py_compile src/app/server.wsgi && \
  echo "👍 server.wsgi syntax is valid"

How it Works

  • python3 -m py_compile <file> attempts to compile the file to bytecode (.pyc)
  • If compilation succeeds, the command after && runs (our little “syntax is good” message)
  • If there’s a syntax error, Python prints the error and the success message won’t appear

Programmatic Usage

You can also do this programmatically in Python:

import py_compile

try:
    py_compile.compile("src/app/analysis.py", doraise=True)
    print("💡 analysis.py syntax is valid")
except py_compile.PyCompileError as e:
    print(f"❌ Syntax error: {e.msg}")

This is a super lightweight way to sanity-check code, add to CI pipelines, or run in pre-commit hooks, without ever executing the script.

More info: py_compile documentation