Overview:
- def keyword in Python is used for defining a function. It is synonymous with the word definition.
- In case of classes the def keyword is used for defining the methods of a class.
- Note that the keyword self needs to be passed as the first parameter in member function definitions.
- def keyword is also required to define special member function of a class like __init__().
Example 1:
In this example Python program a function is defined using the def keyword.
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import math
def areaOfTheCircle(radius): return math.pi*radius*radius
radiusValue = 2 circleArea = areaOfTheCircle(radiusValue) print("Area of the circle with %f units radius is %f units"%(radiusValue, circleArea)); |
Output 1:
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Area of the circle with 2.000000 units radius is 12.566371 units |
Example 2:
In this example Python program a method of a class is defined using the def keyword.
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import math
class Circle: myRadius = 0
def __init__(self, radius): self.myRadius = radius
def area(self): return math.pi*self.myRadius*self.myRadius
radius = 5 circle = Circle(radius) print("Area of the circle with %f units radius is %f units"%(radius, circle.area()));
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Output2:
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Area of the circle with 5.000000 units radius is 78.539816 units |