Welcome, guest | Sign In | My Account | Store | Cart

This code helps you figure out your BMI! Can perform three calculations. Also has a built in quit function. NEW! now can figure up to 10 calculations! I also have a metric version here: http://code.activestate.com/recipes/577907-bmi-calculator-metric/

Python, 54 lines
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
#!/usr/bin/env python

##Author: Alex Cruz

# If user types in q, program terminates
# If user types in other than q, program
# continues and calcualtes bmi
def main():
  quit = False
  count = 0

  answer = raw_input('\nEnter "q" to quit: ')
  if answer == 'q':
      quit = True

# Caclulates bmi 3 times prompting user to type in 'q'
# or another letter to continue with bmi calculation
  while (not quit and count < 10):
      print '-------------------------'
      print 'This is to '
      print '-------------------------'
      weight = float(input('Enter weight in pounds: '))
      height = float(input('Enter height in inches: '))

# Weight cannot be less than 0 or greater than 500
      if weight <= 0 or weight > 500:
          print 'Weight cannot be less than 0 or greater than 500'
          continue

# Height cannot be less than or equal to 0 inches
      elif height <= 0:
          print 'Height cannot be less than 0'
          continue
      else:
          bmi = (weight / (height * height)) * 703.0
          print 'Your BMI is %.2f' % bmi
          if bmi <= 18.5:
              print 'Your weight status is Underweight'
          elif bmi >= 18.5 and bmi <= 24.9:
              print 'Your weight status is Normal weight'
          elif bmi >= 25 and bmi <= 29.9:
              print 'Your weight status is Overweight'
          elif bmi >= 30:
              print 'Your weight status is Obese'

# increments bmi calculation by 1 with a total of 3 bmi calculations
      count = count + 1
      if count < 10:
        answer = raw_input('\nEnter "q" to quit: ')
        if answer == 'q':
            quit = True

main()
raw_input('\n<enter> to exit')

Tell me if you have any improvements you would like to see.

3 comments

Alexander Thomas Cruz (author) 11 years, 2 months ago  # | flag

You can change two numbers to make it do more calculations.

Michal Niklas 11 years, 1 month ago  # | flag

I think you don't need comment code where the same information is displayed in message: "Weight cannot be less than 0 or greater than 500". This way if you change requirements you will have to remember to change it in 3 places: comment, conditional and message. I prefer making constants like MAX_WEIGTH and code like:

# check if weight is reasonable
if weight <= MIN_WEIGHT or weight > MAX_WEIGHT:
  print('Weight cannot be less than %d or greater than %d' % (MIN_WEIGHT, MAX_WEIGHT))

And why only imperial units? I don't know if you can check locale to see if metric system is more useful. Also you can use command line arguments; maybe something like:

bmi.py -metic -weight=75 -height=178
Alexander Thomas Cruz (author) 11 years, 1 month ago  # | flag

I considered the metric problem and forked this recipe.

Created by Alexander Thomas Cruz on Sat, 8 Oct 2011 (MIT)
Python recipes (4591)
Alexander Thomas Cruz's recipes (3)

Required Modules

  • (none specified)

Other Information and Tasks