kfzy3STU

1#**********************************************************************
2# Description:
3# Tests if a field exists and outputs two booleans:
4#   Exists - true if the field exists, false if it doesn't exist
5#   Not_Exists - true if the field doesn't exist, false if it does exist
6#                (the logical NOT of the first output).
7#
8# Arguments:
9#  0 - Table name
10#  1 - Field name
11#  2 - Exists (boolean - see above)
12#  3 - Not_Exists (boolean - see above)
13#
14# Created by: ESRI
15#**********************************************************************
16
17# Standard error handling - put everything in a try/except block
18#
19try:
20
21    # Import system modules
22    import sys, string, os, arcgisscripting
23
24    # Create the Geoprocessor object
25    gp = arcgisscripting.create()
26
27    # Get input arguments - table name, field name
28    #
29    in_Table = gp.GetParameterAsText(0)
30    in_Field = gp.GetParameterAsText(1)
31
32    # First check that the table exists
33    #
34    if not gp.Exists(in_Table):
35        raise Exception, "Input table does not exist"
36
37    # Use the ListFields function to return a list of fields that matches
38    #  the name of in_Field. This is a wildcard match. Since in_Field is an
39    #  exact string (no wildcards like "*"), only one field should be returned,
40    #  exactly matching the input field name.
41    #
42    fields = gp.ListFields(in_Table, in_Field)
43
44    # If ListFields returned anything, the Next operator will fetch the
45    #  field. We can use this as a Boolean condition.
46    #
47    field_found = fields.Next()
48
49    # Branch depending on whether field found or not. Issue a
50    #  message, and then set our two output variables accordingly
51    #
52    if field_found:
53        gp.AddMessage("Field %s found in %s" % (in_Field, in_Table))
54        gp.SetParameterAsText(2, "True")
55        gp.SetParameterAsText(3, "False")
56    else:
57        gp.AddMessage("Field %s not found in %s" % (in_Field, in_Table))
58        gp.SetParameterAsText(2, "False")
59        gp.SetParameterAsText(3, "True")
60
61
62# Handle script errors
63#
64except Exception, errMsg:
65
66    # If we have messages of severity error (2), we assume a GP tool raised it,
67    #  so we'll output that.  Otherwise, we assume we raised the error and the
68    #  information is in errMsg.
69    #
70    if gp.GetMessages(2):   
71        gp.AddError(GP.GetMessages(2))
72    else:
73        gp.AddError(str(errMsg))