# If the python interpreter is running that module (the source file)

# as the main program, it sets the special __name__ variable to have

# a value “__main__”. If this file is being imported from another 

# module, __name__ will be set to the module’s name.

if __name__=='__main__':

  # do something

if __name__=='__main__':

​

#This is a way of executing your code if it runs directly from your system.

#This means that your code was not 'imported', but executed directly.

​

if __name__ == "__main__":

    #execute my code...

# Python program to execute

# main directly

print ("Always executed")

if __name__ == "__main__":

    print ("Executed when invoked directly")

else:

    print ("Executed when imported")

# Python program to execute

# main directly

print ("Always executed")

if __name__ == "__main__":

    print ("Executed when invoked directly")

else:

    print ("Executed when imported")

# Suppose this is foo.py.

​

print("before import")

import math

​

print("before functionA")

def functionA():

    print("Function A")

​

print("before functionB")

def functionB():

    print("Function B {}".format(math.sqrt(100)))

​

print("before __name__ guard")

if __name__ == '__main__':

    functionA()

    functionB()

print("after __name__ guard")

​

if __name__ == "__main__"

​

// Every Python module has it’s __name__ defined 

// and if this is ‘__main__’, 

// it implies that the module is being run 

// standalone by the user and we can do corresponding

// appropriate actions.

​

// If you import this script as a module 

// in another script,

// the __name__ is set to the name

// of the script/module.

// Python files can act as either reusable modules, 

// or as standalone programs.

​

// if __name__ == “main”: is used to execute some 

// code only if the file was run directly, 

// and not imported.

basically,   (__name__ == '__main__') ==True

​

confirms file is NOT a/part of a module and may continue execution  

if __name__ == "__main__": main()

​

# Suppose this is foo.py.

​

print("before import")

import math

​

print("before functionA")

def functionA():

    print("Function A")

​

print("before functionB")

def functionB():

    print("Function B {}".format(math.sqrt(100)))

​

print("before __name__ guard")

if __name__ == '__main__':

    functionA()

    functionB()

print("after __name__ guard")

​

​

​