BMI_calculator.py

# The lines 'from tkinter import*', 'from tkinter.messagebox import *', and 'from tkinter.ttk import*'
# are importing all the classes, functions, and constants from the respective modules into the current
# namespace.
from tkinter import *
from tkinter.messagebox import *
from tkinter.ttk import *

# This block of code is setting up the graphical user interface (GUI) elements for a BMI calculator
# application using the Tkinter library in Python. Here's a breakdown of what each line is doing:
bmi = Tk()
bmi.configure(bg="dark orange")
bmi.geometry("500x600")
bmi.title("bmi calculator made by Chris")
labelweight = Label(bmi, text="Enter your weight in kg")
labelheight = Label(bmi, text="Enter your height in cm")
labelresult = Label(bmi, text="Your BMI value is:")
labelcategory = Label(bmi, text="Your BMI index lies on this category")
optweight = Combobox(bmi, values=["kg", "lbs"])
optheight = Combobox(bmi, values=["cm", "inches"])
entryweight = Entry(bmi)
entryheight = Entry(bmi)
entryres = Entry(bmi)
bmicategory = Entry(bmi)

# The lines 'global bmivalue' and 'global BMIcat' are declaring the variables 'bmivalue' and 'BMIcat'
# as global variables within the current scope. This means that these variables can be accessed and
# modified from anywhere within the program, including inside functions like 'calculate()' and
# 'definecategory()'. By using the 'global' keyword, you are indicating that these variables should
# refer to the same global variable throughout the program, rather than creating new local variables
# with the same names inside functions.
global bmivalue
global BMIcat


def calculate():
    """
    This Python function calculates BMI based on weight and height inputs in either
    kilograms/centimeters or pounds/inches.
    """
    weight = float(entryweight.get())
    height = float(entryheight.get())
    if optweight.get() == "kg" and optheight.get() == "cm":
        bmivalue = weight/((height/100)**2)
        entryres.insert(0, bmivalue)
    if optweight.get() == "kg" and optheight.get() == "inches":
        bmivalue = weight/((height * 0.0254)**2)
        entryres.insert(0, bmivalue)
    if optweight.get() == "lbs" and optheight.get() == "cm":
        bmivalue = (weight * 0.453592)/((height/100)**2)
        entryres.insert(0, bmivalue)
    if optweight.get() == "lbs" and optheight.get() == "inches":
        bmivalue = (weight * 0.453592)/((height * 0.0254)**2)
        entryres.insert(0, bmivalue)


def definecategory():
    """
    This Python function calculates the BMI category based on weight and height inputs.
    """
    weight = float(entryweight.get())
    height = float(entryheight.get())
    bmivalue = weight/((height/100)**2)
    if bmivalue <= 18.5:
        BMIcat = "underweight"
        bmicategory.insert(0, BMIcat)
    if bmivalue > 18.5 and bmivalue <= 25:
        BMIcat = "normal"
        bmicategory.insert(0, BMIcat)
    if bmivalue > 25 and bmivalue <= 30:
        BMIcat = "overweight"
        bmicategory.insert(0, BMIcat)
    if bmivalue > 30 and bmivalue <= 35:
        BMIcat = "obese"
        bmicategory.insert(0, BMIcat)
    if bmivalue > 35:
        BMIcat = "extremly obese"
        bmicategory.insert(0, BMIcat)


# This block of code is responsible for setting up the layout of the graphical user interface (GUI)
# elements for the BMI calculator application. Here's a breakdown of what each line is doing:
calculateButton = Button(bmi, text="calculate bmi", command=calculate)
defineButton = Button(bmi, text="define category", command=definecategory)
labelweight.grid(row=0, column=0)
labelheight.grid(row=1, column=0)
entryweight.grid(row=0, column=1)
entryheight.grid(row=1, column=1)
optweight.grid(row=0, column=2)
optheight.grid(row=1, column=2)
calculateButton.grid(row=2, column=0)
entryres.grid(row=2, column=1)
labelcategory.grid(row=3, column=0)
bmicategory.grid(row=3, column=1)
defineButton.grid(row=4, column=0)


if __name__ == "__main__":
    bmi.mainloop()