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Python formatting update - including named completions

Archive - Originally posted on "The Horse's Mouth" - 2015-12-10 02:31:01 - Graham Ellis

As from Python 2.6, a format method has been introduced in addtion to the % operator on strings to provide a more flexible and improved way of convering objects (of various type) into strings. Select [here] to open the source in a new window which was used to get this result:

  munchkin:cambx grahamellis$ python3 earlier 
  How all are ya (in metres) 1.76
  How heavy are ya (in kgs) 74
  Your bmi is 23.889 if so
  Your bmi is 000023.889 if so
  Your bmi is     23.889 if so
  Your bmi is 23.889     if so
  Your bmi is   23.889   if so
  Your bmi is     23.889 if so
  Your bmi is 23.889462809917354 if so
  for height 1.76 and weight 74.0 the bmi is     23.889
  for height 1.76 and weight 74.0 the bmi is     23.889
  for height 1.76 and weight 74.0 the bmi is     23.889
  munchkin:cambx grahamellis$

This new format method on a string is what we recommend you use in Python 3 ... it has a much inreased flexibility, and indeed allows you to write much cleaner code too - for example by filling in format elements by name:

  print ("Your bmi is {result} if so".format(result=bmi))

or indeed

  result = {"height":h, "weight":w, "bmi":bmi}
  print ("for height {height} and weight {weight} the bmi is {bmi:10.3f}".format(**result))