failed to Writing conditional (if/then) statements into Field Calculator of ArcGIS for Desktop using Python parser?

Question

I wrote this following several examples but it is still wrong. I need to populate a new field based on 5 ranges of values.

    def marks(Wards for try.JHRatio ): 
  if (Wards for try.JHRatio <= 50): 
     return 0
  elif Wards for try.JHRatio >50 and Wards for try.JHRatio <= 90):
     return 1
  elif (Wards for try.JHRatio >90 and  Wards for try.JHRatio <= 110):
     return 2
  elif (Wards for try.JHRatio >= 110 and  Wards for try.JHRatio <= 500):
     return 1
  elif (Wards for try.JHRatio > 500):
     return 0


    marks(!Wards for Try.JHRatio!)

Answer 1

you should use a simple variable name in your function : spaces will cause syntax errors (by the way, I recommend avoiding spaces in file names). it also makes your code more readable. Note that you do not need to do the ">" tests in your case, because the if statement already handle it.

   def marks(myfield): 
      if myfield <= 50: 
         return 0
      elif  myfield <= 90:
         return 1
      elif myfield <= 110:
         return 2
      elif myfield <= 500:
         return 1
      else:
         return 0


    marks(!Wards for Try.JHRatio!)