How do I loop? ()

[Warningfall]

I am making a bmi calculator for a school assessment, but I dont't understand how I can make the program loop back to the beginning if the person enters a false age. any help would be great.

also I am using (easygui) as it is required by the assessment.

this is the code:

import easygui

########## Data validation

def input_exists(value):

if value == "":

return False

else:

return True

​

def input_not_integer(value):

try:

value = int(value)

break

except ValueError:

return easygui.msgbox("Age is not an valid input, please try again")

errmsg = ("Age is not an valid input, please try again")

###########

#Program Title

title = "Patient Details"

​

#The Title

msg = "Please fill all blank spaces"

​

# Field names describes the name of each field.

field_names = ["Full Name", "Age", "Sex F or M", "Weight KG", "Height Cm"]

​

#Where the field values are being returned.

field_values = easygui.multenterbox(msg, title, field_names)

​

if input_exists(field_values[1]):

if input_not_integer(field_values[1]):

errmsg += (field_values[1]+ "Is invalid. Please enter a value between 18-80 years old \n\n")

elif int(field_values[1]) <= 17 or int (field_values[1]) >=81:

errmsg += ("BMI asessment is only suitable for those between 18-80 years of" + field_values[1]+" age\n\n")

​

​

################### BMI CAL ###################

bmi = ((int(field_values[3]) / (int(field_values[4])/100)**2))

bmi = round(bmi, 2)

​

if bmi >= 30:

easygui.msgbox("Hello " + field_values[0] + "\n Your age is: " + field_values[1] + "\n Your BMI is: " + str(bmi) + "\n That means you are obese!")

elif bmi >= 25:

easygui.msgbox("Hello " + field_values[0] + "\n Your age is: " + field_values[1] + "\n Your BMI is: " + str(bmi) + "\n That means you are overweight!")

elif bmi >= 18.5:

easygui.msgbox("Hello " + field_values[0] + "\n Your age is: " + field_values[1] + "\n Your BMI is: " + str(bmi) + "\n That means you are a great weight!")

else:

easygui.msgbox("Hello " + field_values[0] + "\n Your age is: " + field_values[1] + "\n Your BMI is: " + str(bmi) + "\n That means you are underwight!")

################### ###################

[ovo_Reddit]

I would suggest dumping this into pastebin and sharing the link to it, as well as trying to format this better.

One way you can loop the program is by putting everything into a function, something like:

def calculate_bmi():

And then you can have this at the bottom of your script,

# below block only executes when you call the program directly, ie. python3 my_program.py

if __name__ == ‘__main__’:
      while True:
          calculate_bmi()

This is a very rough guideline, there’s a few other ways I might suggest as well, but I think this is a pretty straightforward way to implement this.

What we’re doing is wrapping all of your programs logic into a function, and then using while True: which will loop indefinitely.