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Python Writing to Files

if __name__ == '__main__':

why we are using it when we can just call the function normally

1 Answer

Christopher Shaw
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Christopher Shaw
Python Web Development Techdegree Graduate 58,248 Points

The code here is executed when the file is 'run' from the command line. for example if we had a file called hello.py with the following contents. When you run python hello.py from the command line, it will excute main_function(). However if you import hello.py, it will not run.

def main_function():
    print("Hello World")

if __name__ == '__main__': 
Chris Howell
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Chris Howell
Python Web Development Techdegree Graduate 49,702 Points

To add onto this answer. Lets pretend we have a two files called import_me.py and test_me.py that looks like this.


def print_hello():

print("this is import_me.py")

Now from another file called, lets say test_me.py


import import_me

print("This is the test_me.py Script")

I would tell Python to run the test_me.py script

python test_me.py

You would get this output.


this is the import_me.py
This is the test_me.py Script