Perfect Squares Python-CodePudding

I have been trying to write a code that is suppose to return perfect squares using object oriented programming from given values from a instance variable. Below is what I have written and still I was was not able to get perfect squares. Below is what I have written

# Write a class, PerfectSquares, that implements an iterator<br>
# This will return 1, 4, 9, 25, 36, 49, etc.

class PerfectSquares:
    def __init__(self, x):
        self.x = x
        
    def get_values(self):
        return self.x**2

values = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for i in values:
    getter = values.get_values(i)
    print(getter)

CodePudding user response：

You should implement both __iter__ and __next__ methods.

Iterator objects in python conform to the iterator protocol, which basically means they provide two methods: __iter__ and __next__.

The iter returns the iterator object and is implicitly called at the start of loops.
The next() method returns the next value and is implicitly called at each loop increment. This method raises a StopIteration exception when there are no more value to return, which is implicitly captured by looping constructs to stop iterating.

A good resource for iterators: https://www.ibm.com/developerworks/library/l-pycon/

class PerfectSquares:
    """Class to implement an iterator
    of perfect squares"""

    def __init__(self, k):
        self.k = k
        self.n = 0

    def __iter__(self):
        return self

    def __next__(self):
        self.n  = 1
        if self.n <= self.k:
            result = self.n ** 2
            return result
        else:
            raise StopIteration
v = PerfectSquares(10)
for i in v:
    print(i)

This will output:

CodePudding user response：

First, You have to create an Object of the class and pass value. (obj = PerfectSquares(i))
Second, Call the get_values method with that obj without passing any arguments, because get_values is not taking any.
Third, print the variable.

Refer the code below:

class PerfectSquares:
    def __init__(self, x): # this constructor takes an argument 'x'.
        self.x = x
        
    def get_values(self): # this function takes no argument.
        return self.x**2

values = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
for i in values:
    obj = PerfectSquares(i) # 'i' variable is passed to 'x' in class.
    getter = obj.get_values() # returns the square of 'i' ('x' in class).
    print(getter)

Output: