FieldPyculator Plugin - How to Classify Fields?

Question

Could someone tell me how to classify/populate fields with QGIS FieldPyculator Plugin?

In the Attribute Table, I have a field named POPULACAO with population data:

I want to apply a weight to classify these fields. I've installed QGIS FieldPyculator Plugin via repository. Below the Python code to complete this task in ArcGIS 10:

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def reclass(POP):

if (POP <= 10000):
return 1
elif (POP > 10001 and POP <= 30000):
return 2
elif (POP > 30001 and POP <= 50000):
return 3
elif (POP > 50001 and POP <= 100000):
return 4
elif (POP > 100001 and POP <= 200000):
return 5
elif (POP > 200001 and POP <= 500000):
return 6
elif (POP > 500001 and POP <= 1000000):
return 7
else:
return 8

In the box below:

reclass( !POPULACAO! )

The ArcGIS 10 Python code works like a charm. Data shapefile: http://bit.ly/xBW8Pz | In FieldPyculator, I did wrong, I know:

Please help me. Jorge Santos

Answer 1

Well, the error message says that the indentation is wrong. The code is not correctly indented at all. In Python, indentation matters and everything after the first line would have to be indented, as well as all the loops etc.

Answer 2

Standard Python indentation is two or four spaces.
Try using the following indented code:

def reclass(POP):
  if (POP <= 10000):
    return 1
  elif (POP > 10001 and POP <= 30000):
    return 2
  elif (POP > 30001 and POP <= 50000):
    return 3
  elif (POP > 50001 and POP <= 100000):
    return 4
  elif (POP > 100001 and POP <= 200000):
    return 5
  elif (POP > 200001 and POP <= 500000):
    return 6
  elif (POP > 500001 and POP <= 1000000):
    return 7
  else:
    return 8

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