Pass Statement

Overview:

  • pass is a keyword in Python.

 

  • pass keyword constitutes a pass statement.

 

  • pass denotes a null operation. Nothing happens when pass is executed.

 

  • pass is not equivalent to a comment statement in Python.

 

  • Unlike a comment statement a pass statement in Python is not ignored.

 

  • In function blocks, method blocks, if blocks and for blocks - a Python developer can use a statement alone denoting the implementation of the block is to be done later.

 

  • Blocks only with pass statements make the design intentions of the developer clear and explicit.

 

  • A function or method with a pass statement returns None.

 

Example 1:

def mean():

    pass

 

z = mean()   

print(z)

 

Output:

None

 

The above definition of function mean()is deferred with a pass statement.

 

Example 2:

class image:

    def translate(self):

        print("translation done")    # the real implementation will be much more

 

    def rotate(self):

        print("rotation done")       # the real implementation will be much more

       

    def add(self):

        pass # adding two images is for sprint 2

 

imageObject = image()

 

# Test image operations

imageObject.translate()

imageObject.rotate()

imageObject.add()

 

Output:

translation done

rotation done

 

In the above example implementation rotation method of an image object is marked for sprint 2 and filled with a pass statement.


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