pyBMI-Calculator

def get_float(prompt):
    while True:
        s = input("\n" + prompt)
        try:
            return s, float(s)      # return the original string AND the float value
        except:
            print("Invalid input. Please re-enter")

while True:
    height_str, height_float = get_float("Enter your height in metres: ")
    if 1.35 < height_float < 2.1:
        break
    print("Height out of acceptable range. Please re-enter")

while True:
    weight_str, weight_float = get_float("Enter your weight in Kg: ")
    if 35 < weight_float < 120:
        break
    print("Weight out of acceptable range. Please re-enter")

bmi = weight_float / (height_float ** 2)
cats = [-1, "severely underweight", 15, "underweight", 18.5, "normal", 25, "overweight",
        30, "moderately obese", 35, "severely obese", 40, "morbidly obese"]

for x in range(0, len(cats), 2):
    if bmi >= cats[x]:
        text = cats[x+1]
print(f"\nBased on your weight of {weight_str} Kg, and your height of {height_str} metres, your BMI rating is {text}")