added more questions

Author: xcao21

100+ Python challenging programming exercises.txt

@@ -1105,5 +1105,255 @@ print tp2
 
 
 
+#----------------------------------------#
+2.14
+
+Question:
+Write a program which accepts a string as input to print "Yes" if the string is "yes" or "YES" or "Yes", otherwise print "No". 
+
+Hints:
+
+Use if statement to judge condition.
+
+Solution
+s= raw_input()
+if s=="yes" or s=="YES" or s=="Yes":
+    print "Yes"
+else:
+    print "No"
+
+
+
+#----------------------------------------#
+3.4
+
+Question:
+Write a program which can filter even numbers in a list by using filter function. The list is: [1,2,3,4,5,6,7,8,9,10].
+
+Hints:
+
+Use filter() to filter some elements in a list.
+Use lambda to define anonymous functions.
+
+Solution
+li = [1,2,3,4,5,6,7,8,9,10]
+evenNumbers = filter(lambda x: x%2==0, li)
+print evenNumbers
+
+
+#----------------------------------------#
+3.4
+
+Question:
+Write a program which can map() to make a list whose elements are square of elements in [1,2,3,4,5,6,7,8,9,10].
+
+Hints:
+
+Use map() to generate a list.
+Use lambda to define anonymous functions.
+
+Solution
+li = [1,2,3,4,5,6,7,8,9,10]
+squaredNumbers = map(lambda x: x**2, li)
+print squaredNumbers
+
+#----------------------------------------#
+3.5
+
+Question:
+Write a program which can map() and filter() to make a list whose elements are square of even number in [1,2,3,4,5,6,7,8,9,10].
+
+Hints:
+
+Use map() to generate a list.
+Use filter() to filter elements of a list.
+Use lambda to define anonymous functions.
+
+Solution
+li = [1,2,3,4,5,6,7,8,9,10]
+evenNumbers = map(lambda x: x**2, filter(lambda x: x%2==0, li))
+print evenNumbers
+
+
+
+
+#----------------------------------------#
+3.5
+
+Question:
+Write a program which can filter() to make a list whose elements are even number between 1 and 20 (both included).
+
+Hints:
+
+Use filter() to filter elements of a list.
+Use lambda to define anonymous functions.
+
+Solution
+evenNumbers = filter(lambda x: x%2==0, range(1,21))
+print evenNumbers
+
+
+#----------------------------------------#
+3.5
+
+Question:
+Write a program which can map() to make a list whose elements are square of numbers between 1 and 20 (both included).
+
+Hints:
+
+Use map() to generate a list.
+Use lambda to define anonymous functions.
+
+Solution
+squaredNumbers = map(lambda x: x**2, range(1,21))
+print squaredNumbers
+
+
+
+
+#----------------------------------------#
+7.2
+
+Question:
+Define a class named American which has a static method called printNationality.
+
+Hints:
+
+Use @staticmethod decorator to define class static method.
+
+Solution
+class American(object):
+    @staticmethod
+    def printNationality():
+        print "America"
+
+anAmerican = American()
+anAmerican.printNationality()
+American.printNationality()
+
+
+
+
+#----------------------------------------#
+
+7.2
+
+Question:
+Define a class named American and its subclass NewYorker. 
+
+Hints:
+
+Use class Subclass(ParentClass) to define a subclass.
+
+Solution:
+
+class American(object):
+    pass
+
+class NewYorker(American):
+    pass
+
+anAmerican = American()
+aNewYorker = NewYorker()
+print anAmerican
+print aNewYorker
+
+
+
+
+#----------------------------------------#
+
+
+7.2
+
+Question:
+Define a class named Circle which can be constructed by a radius. The Circle class has a method which can compute the area. 
+
+Hints:
+
+Use def methodName(self) to define a method.
+
+Solution:
+
+class Circle(object):
+    def __init__(self, r):
+        self.radius = r
+
+    def area(self):
+        return self.radius**2*3.14
+
+aCircle = Circle(2)
+print aCircle.area()
+
+
+
+
+
+
+#----------------------------------------#
+Define a class named Rectangle which can be constructed by a length and width. The Rectangle class has a method which can compute the area. 
+
+Hints:
+
+Use def methodName(self) to define a method.
 
+Solution:
+
+class Rectangle(object):
+    def __init__(self, l, w):
+        self.length = l
+        self.width  = w
+
+    def area(self):
+        return self.length*self.width
+
+aRectangle = Rectangle(2,10)
+print aRectangle.area()
+
+
+
+
+#----------------------------------------#
+Define a class named Shape and its subclass Square. The Square class has an init function which takes a length as argument. Both classes have a area function which can print the area of the shape where Shape's area is 0 by default.
+
+Hints:
+
+To override a method in super class, we can define a method with the same name in the super class.
+
+Solution:
+
+class Shape(object):
+    def __init__(self):
+        pass
+
+    def area(self):
+        return 0
+
+class Square(Shape):
+    def __init__(self, l):
+        Shape.__init__(self)
+        self.length = l
+
+    def area(self):
+        return self.length*self.length
+
+aSquare= Square(3)
+print aSquare.area()
+
+
+
+
+
+
+
+
+#----------------------------------------#
+
+
+
+
+
+
+
+#----------------------------------------#