In [9]:
#when we run python program some variables are first set up by default.
#__name__ is one of variable which is set to __main__ when run directly but if we import the module it will take the value of module name
print("Name: {}".format(__name__))

Name: __main__
In [10]:
#Example
import subprocess
subprocess.getoutput("cat module.py")
#we can see that module.py has same code as above statement. and now if i import it
Out[10]:
'print("Name: {}".format(__name__))'
In [15]:
import module
#in place of "__name__" module is there as are not running it directly we are importing it.

Name: module
In [17]:
#In python this is used alot
def main():
    print("Name: {}".format(__name__))

if __name__ == '__main__':  
#we set the condition checks whether the file is directly run by python or imported.
    main()

#we can see our print statement gets executed as we are running it directly.

Name: __main__
In [18]:
#this file has same code as above code block.
subprocess.getoutput("cat second_module.py")
#image \n as next line..
Out[18]:
'def main():\n    print("Name: {}".format(__name__))\n\nif __name__ == \'__main__\':\n    main()'
In [19]:
#when i import this code
import second_module
#print doesn't as executed as if statement get failed.
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