Python - Age Calculator using PyQt

# importing libraries
from PyQt5.QtWidgets import * 
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import * 
from PyQt5.QtCore import * 
import sys


class Window(QMainWindow):

    def __init__(self):
        super().__init__()

        # setting title
        self.setWindowTitle("Age calculator")

        # setting geometry
        self.setGeometry(100, 100, 500, 400)

        # calling method
        self.UiComponents()

        # showing all the widgets
        self.show()

    # method for components
    def UiComponents(self):

        # creating head label
        head = QLabel("Age Calculator", self)

        # setting geometry to the head
        head.setGeometry(100, 10, 300, 60)

        # font
        font = QFont('Times', 14)
        font.setBold(True)
        font.setItalic(True)
        font.setUnderline(True)

        # setting font to the head
        head.setFont(font)

        # setting alignment of the head
        head.setAlignment(Qt.AlignCenter)
        head.setStyleSheet("color : green;")


        # D.O.B label
        dob = QLabel("Date of Birth", self)

        # setting geometry
        dob.setGeometry(0, 80, 250, 50)

        # setting alignment and font
        dob.setAlignment(Qt.AlignCenter)
        dob.setFont(QFont('Times', 10))

        # given date label
        given = QLabel("Given Date", self)

        # setting geometry
        given.setGeometry(300, 80, 250, 50)

        # setting alignment and font
        given.setAlignment(Qt.AlignCenter)
        given.setFont(QFont('Times', 10))

        # creating a QDateEdit to get the d.o.b
        self.first = QDateEdit(self)

        # setting geometry
        self.first.setGeometry(25, 130, 200, 50)

        # setting font and alignment
        self.first.setAlignment(Qt.AlignCenter)
        self.first.setFont(QFont('Arial', 9))

        # adding action to the first
        # when date get change
        self.first.dateChanged.connect(self.first_action)

        # creating a QDateEdit to get the given date
        self.second = QDateEdit(self)

        # setting geometry
        self.second.setGeometry(275, 130, 200, 50)

        # setting font and alignment
        self.second.setAlignment(Qt.AlignCenter)
        self.second.setFont(QFont('Arial', 9))

        # adding action to the second
        # when date get change
        self.second.dateChanged.connect(self.second_action)

        # create a push button for calculate
        calculate = QPushButton("Calculate", self)

        # setting geometry to the push button
        calculate.setGeometry(200, 210, 100, 40)

        # setting color effect to the push button
        color = QGraphicsColorizeEffect()
        color.setColor(Qt.darkGreen)
        calculate.setGraphicsEffect(color)

        # adding action to the calculate button
        calculate.clicked.connect(self.find_age)

        # creating a result label to show the ans
        self.result = QLabel(self)

        # setting geometry
        self.result.setGeometry(50, 280, 400, 80)

        # setting style sheet and the font
        self.result.setAlignment(Qt.AlignCenter)
        self.result.setFont(QFont('Times', 12))

        # setting stylesheet
        self.result.setStyleSheet("QLabel"
                                  "{"
                                  "border : 2px solid black;"
                                  "background : lightgrey;"
                                  "}")

        # making label multi line
        self.result.setWordWrap(True)

        # set dates to the first and second
        self.first.setDate(QDate(2000, 1, 1))
        self.second.setDate(QDate(2020, 1, 1))


    # method called by the first date edit
    def first_action(self):

        # get the second date
        date = self.second.date()

        # set the maximum date in first
        self.first.setMaximumDate(date)

    # method called by the first date edit
    def second_action(self):

        # get the first date
        date = self.first.date()

        # set the maximum date in first
        self.second.setMinimumDate(date)


    # method called by the push button
    def find_age(self):

        # get the first age
        get_Qdate1 = self.first.date()
        birth_year = get_Qdate1.year()
        birth_month = get_Qdate1.month()
        birth_day = get_Qdate1.day()

        # get the second age
        get_Qdate2 = self.second.date()
        given_year = get_Qdate2.year()
        given_month = get_Qdate2.month()
        given_day = get_Qdate2.day()

        # if birth date is greater then given birth_month
        # then donot count this month and add 30 to the date so
        # as to subtract the date and get the remaining days
        month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

        if (birth_day > given_day):
            given_month = given_month - 1
            given_day = given_day + month[birth_month - 1]

        # if birth month exceeds given month, then
        # donot count this year and add 12 to the
        # month so that we can subtract and find out
        # the difference
        if (birth_month > given_month):
            given_year = given_year - 1
            given_month = given_month + 12

        # calculate day, month, year
        calculated_day = given_day - birth_day
        calculated_month = given_month - birth_month
        calculated_year = given_year - birth_year

        # setting text to the result
        self.result.setText(str(calculated_day) + " Day(s), " + str(calculated_month)
                            + " Month(s), " + str(calculated_year) + " Year(s)")



    # create pyqt5 app
App = QApplication(sys.argv)

# create the instance of our Window
window = Window()

# start the app
sys.exit(App.exec())