I have a featureclass (in a File Geodatabase), with a particular field of type Double. I want to copy it over to a text field, so that only 3 decimal places are shown.

For example: 34.78902345 becomes 34.789

I have gone through this question: How to convert a double field to a string?, but that does not solve my issue. I have even tried to format the double field, but even then the text field contains all the decimals.

How do I do this in ArcGIS 10.0?


You should be able to use string formatting:



>>> '{0:.3f}'.format(34.78902345)

Here is the Python string formatting cookbook for reference.

To use this in the field calculator you can create a function:

def my_format(val):
  return '{0:.3f}'.format(val)

You can use this python function within Field Calculator:

def updateValue(value):
  if value <> '':
    newValue = str(value)
    splitBefore = newValue.split('.')[0]
    splitAfter = newValue.split('.')[1]
    return splitBefore + '.' + splitAfter[:3]
  else: return ''

Name =

updateValue( !yourFieldName!)

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