#!/usr/bin/env python3
"""
Debugging: FixDatTrash # 2
"""

# constant:
PI = 3.1415926535897


class Calculator:
    """A calculator class."""

    def __init__(self, num):
        """Initialize attributes."""
        self.num = num

    def calculate_power(self, exp):
        """
        Calculates power of self.num.
        parameter `exp` is the exponent.
        """
        return self.num ** exp

    def calculate_square_root(self):
        """Calculates square root of self.num."""
        return self.num ** 0.5

    def calculate_cube_root(self):
        """Calculates cube root of self.num."""
        return self.num ** (1 / 3)

    def calculate_circumference(self):
        """
        Calculates circumference of circle.
        self.num is the diameter of the circle.
        """
        return PI * self.num