Using if __name__ == '__main__'
Using if __name__ == '__main__':
in your Python scripts is considered a best practice because it allows you to control the execution of your script when it is imported as a module or run as a standalone script.
When a Python script is run, the interpreter sets a special variable called __name__
. If the script is run as the main program, __name__
is set to '__main__'
. If the script is imported as a module into another script, __name__
is set to the name of the module (i.e., the script's filename without the .py
extension).
By wrapping the main part of your script in a if __name__ == '__main__':
block, you ensure that the code inside the block is executed only when the script is run as the main program. This makes your script more modular and reusable, allowing other scripts to import and use functions or classes defined in your script without executing the main part of the script.
Here's an example:
# my_script.py
def greet(name):
print(f"Hello, {name}!")
def main():
greet("World")
if __name__ == '__main__':
main()
In this example, we define a greet
function and a main
function. The main
function calls the greet
function with the argument "World". We wrap the call to the main
function in a if __name__ == '__main__':
block.
When my_script.py
is run as a standalone script, the main
function is executed, and "Hello, World!" is printed. However, when my_script.py
is imported as a module in another script, the main
function is not executed, but the greet
function can still be used.
# another_script.py
import my_script
my_script.greet("Alice") # This will print "Hello, Alice!" without running the main() function from my_script.py
In summary, using if __name__ == '__main__':
in your scripts allows you to control the execution of your script and make your code more modular and reusable.