How to Call a Python Script from Another Python Script

Are you looking to streamline your Python projects by calling one script from another? This guide will walk you through the process, helping you create more modular and efficient code.

Why Call Python Scripts from Other Scripts?

Calling Python scripts from other scripts allows you to:

• Modularize your code for better organization
• Reuse functions across multiple projects
• Improve code maintainability and readability
• Separate concerns in larger projects

Method 1: Using Import Statements

The most common way to call a Python script from another is by using import statements.

Steps:

1. Ensure both scripts are in the same directory or Python path
2. Use the import statement in your main script
3. Call functions from the imported script

Example:

# In script_to_be_called.py
def greet(name):
    return f"Hello, {name}!"

# In main_script.py
import script_to_be_called

result = script_to_be_called.greet("Alice")
print(result)

Method 2: Using exec() Function

For situations where you need to execute a script dynamically:

exec(open("script_to_be_called.py").read())

Note: Use this method cautiously as it can pose security risks if used with untrusted code.

Method 3: Using subprocess Module

To run a Python script as a separate process:

import subprocess

subprocess.run(["python", "script_to_be_called.py"])

Best Practices

• imports for modular code structure
• Avoid circular imports
• Use if __name__ == “__main__”: to control script execution
• Document your code and functions clearly

Common Pitfalls to Avoid

• Incorrectly setting Python path
• Naming conflicts between scripts
• Overusing global variables across scripts