topic Re: Replacing record from a field with a List in Python Questions

Replacing record from a field with a List

BrunoDeus1 — Sun, 12 Dec 2021 00:41:21 GMT

Hi,

I've Feature Class which keeps changing (e.g. S_pol_Din_DepL82270692015146eAnt015130) and I would like use Arcpy to replace a text (like 2015178eAnt015146) from him field (d2clust200m). Some rows are empty, e.g <Null>, and I don't want change them. But, I can't use replace with a text from ListFeatureClass, it shows that is done, But, isn't.

The text that will be replaced is always the same from the last piece's name from the another FC (it always starts with "pol_din").

If it's too hard be done by arcpy, I can use MB. Or even replace just what isn't null.

Next, I show all tries I've done.

import arcpy
... 
... # Local variables:
... arcpy.env.workspace = r'C:\Teste_Auto_CLEIA\Auto_Classi\Dinamica_GDB.gdb'
...  
... #List FC # line 6
... FC = arcpy.ListFeatureClasses("S_pol_Din*")
... Feature = FC[0]
... print"Feature: "+str(Feature)
... strFeature = str(Feature)
... print"strFeature: "+strFeature
... 
... #List FC # line 13
... FCName = arcpy.ListFeatureClasses("pol*")
... FC_Name = FCName[1]
... print"FC_Name: "+str(FC_Name)
... FCNameCut = FC_Name[-17:]
... print"FCNameCut "+FCNameCut
... 
... #Calculate field (D2clust200m)             #Line 20
... arcpy.CalculateField_management (Feature, "D2clust200m", "!D2clust200m!.replace('"'FCNameCut'"', \"test\")","PYTHON")
... print"Try 1 Calculated"
... 
... #Calculate field (D2clust200m)             
... #arcpy.CalculateField_management (Feature, "D2clust200m", "!D2clust200m!.replace(\"FCNameCut\", \"test\")","PYTHON")
... #print"2nd try Calculated"
... 
... #Calculate field (D2clust200m)              
... #arcpy.CalculateField_management (Feature, "D2clust200m", '!D2clust200m!.replace('"'FCNameCut'"', '"'test'"')',"PYTHON")
... #print"Try 3 Calculated"
... 
... #Calculate field (D2clust200m)  #This one works if I don't use a list's word           
... #arcpy.CalculateField_management (Feature, "D2clust200m", '!D2clust200m!.replace(\"FCNameCut\", \"test\")',"PYTHON")
... #print"4th try Calculated"
... print"Done"‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍
... 
Feature: S_pol_Din_DepL82270692015146eAnt015130
strFeature: S_pol_Din_DepL82270692015146eAnt015130
FC_Name: pol_Din_DepL82270692015178eAnt015146
FCNameCut 2015178eAnt015146
Try 1 Calculated
Done‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Thanks

*I'm using Arcmap 10.4 with Python 2.7, but I appreciate if it works on ArcMap 10.1

Re: Replacing record from a field with a List

RandyBurton — Sun, 12 Dec 2021 00:41:24 GMT

For your field calculator line, do you get better results if you try:

# No quotes (") around FCNameCut 
arcpy.CalculateField_management (Feature, "D2clust200m", '!D2clust200m!.replace(FCNameCut, \"test\")',"PYTHON_9.3")
‍‍

May also want to use "PYTHON_9.3".

Re: Replacing record from a field with a List

BrunoDeus1 — Mon, 19 Feb 2018 05:33:09 GMT

Randy, It didn't works

#Calculate field (D2clust200m) #This one works if I don't use a list's word # Line 20
... arcpy.CalculateField_management (Feature, "D2clust200m", '!D2clust200m!.replace(FCNameCut, \"test\")',"PYTHON_9.3")
... print"Randy 1 try Calculated"
... print"Done"
...
Feature: S_pol_Din_DepL82270692015146eAnt015130
strFeature: S_pol_Din_DepL82270692015146eAnt015130
FC_Name: pol_Din_DepL82270692015178eAnt015146
FCNameCut 2015178eAnt015146
Runtime error Traceback (most recent call last): File "<string>", line 21, in <module> File "c:\program files (x86)\arcgis\desktop10.4\arcpy\arcpy\management.py", line 3360, in CalculateField raise e ExecuteError: ERROR 000539: Error running expression: u"2015178eAnt015146".replace(FCNameCut, "test") Traceback (most recent call last): File "<expression>", line 1, in <module> NameError: name 'FCNameCut' is not defined Failed to execute (CalculateField).

Is there some idea?

Re: Replacing record from a field with a List

DanPatterson_Retired — Mon, 19 Feb 2018 05:44:42 GMT

are you still using this line in your code?

FCNameCut = FC_Name[-17:]

maybe you should show the full cleanedup code prior to trying Randy's suggestion

Re: Replacing record from a field with a List

BrunoDeus1 — Mon, 19 Feb 2018 06:13:27 GMT

Yes, I was using the line. I changed this line, accepted the Randy's tip and cleaned the script. I show the last version:

import arcpy
...
... # Local variables:
... arcpy.env.workspace = r'C:\Teste_Auto_CLEIA\Auto_Classi\Dinamica_GDB.gdb'
...
... #List FC # line 6
... FC = arcpy.ListFeatureClasses("S_pol_Din*")
... Feature = FC[0]
... print"Feature: "+str(Feature)
...
... #List FC # line 11
... FCName = arcpy.ListFeatureClasses("pol*")
... FC_Name = FCName[1]
... print"FC_Name: "+str(FC_Name)
... FCNameCut = FC_Name[19:36] # I changed now
... print"FCNameCut "+FCNameCut
...
... #Calculate field (D2clust200m) #Line 18
... arcpy.CalculateField_management (Feature, "D2clust200m", '!D2clust200m!.replace(FCNameCut, \"test\")',"PYTHON_9.3")
... print"Randy 1 try Calculated"
... print"Done"
...
Feature: S_pol_Din_DepL82270692015146eAnt015130
FC_Name: pol_Din_DepL82270692015178eAnt015146
FCNameCut 2015178eAnt015146
Runtime error Traceback (most recent call last): File "<string>", line 19, in <module> File "c:\program files (x86)\arcgis\desktop10.4\arcpy\arcpy\management.py", line 3360, in CalculateField raise e ExecuteError: ERROR 000539: Error running expression: u"2015178eAnt015146".replace(FCNameCut, "test") Traceback (most recent call last): File "<expression>", line 1, in <module> NameError: name 'FCNameCut' is not defined Failed to execute (CalculateField).

Something else to do?

Re: Replacing record from a field with a List

DanPatterson_Retired — Sun, 12 Dec 2021 00:41:27 GMT

I think replicating the field name in the expression could be an issue. If this doesn't work, then copy the code snippet from the Results window to get the correct syntax. Do this for a few selected records that do not contain <null>

print("FCNameCut is: {}".format(FCNameCut))
if FCNameCut is not None:
    expr = FC_Name.replace(str(FCNameCut), "test")‍
    arcpy.CalculateField_management (Feature, "D2clust200m", expr,"PYTHON_9.3")
‍‍‍‍

Re: Replacing record from a field with a List

XanderBakker — Sun, 12 Dec 2021 00:41:29 GMT

You have to keep in mind that when you use an expression like:

'!D2clust200m!.replace(FCNameCut, \"test\")'‍

... it will use FCNameCut as a string and not its content. You need to have the content and include the quotes to make sure it is interpreted correctly. The expression may require additional quotes due to the double interpretation (python and calculate field parser).

You can also use a cursor to update the values:

with arcpy.da.UpdateCursor(Feature, ('D2clust200m')) as curs:
    for row in curs:
        row[0] = row[0].replace(FCNameCut, "test")
        curs.updateRow(row)
‍‍‍‍

You also have me pretty confused by the way you get the "Feature" and "FC_Name". Listing the featureclasses and get the first item from the first list and second items from the second lists. You don't know how the featureclasses are named? Does each fgdb that you will use this code on have the same content?

Re: Replacing record from a field with a List

BrunoDeus — Mon, 19 Feb 2018 22:54:12 GMT

I tried, but it doesn't works. I tried similar version, none works.

import arcpy
...
... # Local variables:
... arcpy.env.workspace = r'C:\Teste_Auto_CLEIA\Auto_Classi\Dinamica_GDB.gdb'
...
... #List FC # line 6
... FC = arcpy.ListFeatureClasses("S_pol_Din*")
... Feature = FC[0]
... print"Feature: "+str(Feature)
...
... #List AnotherFC # line 11
... FCName = arcpy.ListFeatureClasses("pol*")
... FC_Name = FCName[1]
... print"FC_Name: "+str(FC_Name)
... FCNameCut = FC_Name[19:36] # Isn't original lane
... print"FCNameCut "+FCNameCut
...
... #Calculate field (D2clust200m) #Line 18
... print("FCNameCut is: {}".format(FCNameCut))
... if FCNameCut is not None:
... expr = FC_Name.replace(str(FCNameCut), "test") #I tried with FCNameCut and not with FC_Name too
... arcpy.CalculateField_management (Feature, "D2clust200m", expr,"PYTHON_9.3")
... print"Done"
...
Feature: S_pol_Din_DepL82270692015146eAnt015130
FC_Name: pol_Din_DepL82270692015178eAnt015146
FCNameCut 2015178eAnt015146
FCNameCut is: 2015178eAnt015146
Runtime error Traceback (most recent call last): File "<string>", line 22, in <module> File "c:\program files (x86)\arcgis\desktop10.1\arcpy\arcpy\management.py", line 3129, in CalculateField raise e ExecuteError: ERROR 000539: Error running expression: pol_Din_DepL8227069test Traceback (most recent call last): File "<expression>", line 1, in <module> NameError: name 'pol_Din_DepL8227069test' is not defined Failed to execute (CalculateField).

Re: Replacing record from a field with a List

DanPatterson_Retired — Mon, 19 Feb 2018 23:07:28 GMT

two suggestions... one a repeat...

1. do the calculate field manually and copy the Results window python snippet

2 show a screen grab of the field and the values in it to make sure we are dealing with plausible entries

Re: Replacing record from a field with a List

BrunoDeus — Mon, 19 Feb 2018 23:07:37 GMT

Every week the file's name chenges. The last part of name came's from a data. Both Features Classes at the script are diferente (name and content).

You are right that was confusing about Features Classes, so I explained it better at line 11

I tried your suggest too

import arcpy
...
... # Local variables:
... arcpy.env.workspace = r'C:\Teste_Auto_CLEIA\Auto_Classi\Dinamica_GDB.gdb'
...
... #List FC # line 6
... FC = arcpy.ListFeatureClasses("S_pol_Din*")
... Feature = FC[0]
... print"Feature: "+str(Feature)
...
... #List AnotherFC # line 11
... FCName = arcpy.ListFeatureClasses("pol*")
... FC_Name = FCName[1]
... print"FC_Name: "+str(FC_Name)
... FCNameCut = FC_Name[19:36] # Isn't original lane
... print"FCNameCut "+FCNameCut
...
... #Calculate field (D2clust200m) #Line 18
... with arcpy.da.UpdateCursor(Feature, ('D2clust200m')) as curs:
... for row in curs:
... row[0] = row[0].replace(FCNameCut, "test")
... curs.updateRow(row)
... print"Bakker try"
...
Feature: S_pol_Din_DepL82270692015146eAnt015130
FC_Name: pol_Din_DepL82270692015178eAnt015146
FCNameCut 2015178eAnt015146
Runtime error
Traceback (most recent call last):
File "<string>", line 21, in <module>
AttributeError: 'NoneType' object has no attribute 'replace'

Re: Replacing record from a field with a List

DanPatterson_Retired — Mon, 19 Feb 2018 23:12:22 GMT

NoneType' object has not attribute 'replace'

means this line

row[0] = row[0].......

row[0 is None

Re: Replacing record from a field with a List

RandyBurton — Sun, 12 Dec 2021 00:41:33 GMT

If you want to use the update cursor as Xander Bakker is suggesting, you will need to add a test so you can skip fields with null values:

with arcpy.da.UpdateCursor(Feature, ('D2clust200m')) as curs:
    for row in curs:
        if row[0] is not None:
            row[0] = row[0].replace(FCNameCut, "test")
            curs.updateRow(row)‍‍‍‍‍

Re: Replacing record from a field with a List

PaulSmith8 — Sun, 12 Dec 2021 00:41:35 GMT

Bruno. Try to simplify the problem and what you are trying to do and then build from there.

Try the following code.

import arcpy

fc = r"C:\Teste_Auto_CLEIA\Auto_Classi\Dinamica_GDB.gdb\S_pol_Din_DepL82270692015146eAnt015130"
fieldname = "D2clust200m"
codeblock = "searchtext=\"2015146eAnt015130\""

arcpy.CalculateField_management(fc, fieldname, "!D2clust200m!.replace(searchtext,\"Test\")", "PYTHON_9.3", codeblock)‍‍‍‍‍‍‍

Re: Replacing record from a field with a List

BrunoDeus1 — Tue, 20 Feb 2018 06:48:52 GMT

Script works successfully!!!

Thanks Randy and everyone who helps.

import arcpy
...
... # Local variables:
... arcpy.env.workspace = r'C:\Teste_Auto_CLEIA\Auto_Classi\Dinamica_GDB.gdb'
...
... #List FC # Line 6
... FC = arcpy.ListFeatureClasses("S_pol_Din*")
... Feature = FC[0]
... print"Feature: "+str(Feature)
...
... #List Another FC # Line 11
... FCName = arcpy.ListFeatureClasses("pol*")
... FC_Name = FCName[1]
... print"FC_Name: "+str(FC_Name)
... FCNameCut = FC_Name[19:36] # Isn't original line
... print"FCNameCut "+FCNameCut
...
... #Calculate field (D2clust200m) #Line 18
... with arcpy.da.UpdateCursor(Feature, ('D2clust200m')) as curs:
...   for row in curs:
...   if row[0] is not None:
...   row[0] = row[0].replace(FCNameCut, "test")
...   curs.updateRow(row)
... print"Randy's try"

Re: Replacing record from a field with a List

BrunoDeus1 — Tue, 20 Feb 2018 07:31:05 GMT

Interesting path, but I didn't find a way for switch a text (e.g. 2015178eAnt015146) for a result from a ListFeatureClass

Re: Replacing record from a field with a List

XanderBakker — Tue, 20 Feb 2018 16:47:17 GMT

Good to hear that you were able to solve it using Randy Burton suggestion. Do keep in mind that a field that with Null values will remain Null, which could be what you want. I'm still not convinced about using the list featureclasses and selecting the first or second value from a list. Could you share a list of the content of two file geodatabases to see hoe the names differ and to see if there may be a more "stable" (less error prone) way of getting the featuresclasses you want?

Re: Replacing record from a field with a List

BrunoDeus1 — Thu, 22 Feb 2018 02:46:04 GMT

I have three Feature Classes and all them are at the same geodatabase.

For help you, I send a screen grab that we are talking about.

Good luck.

*Addition info, I know the FeatureClass[1] has the piece's name that I'm looking for. And I don't know how to retrieve the records from the FeatureClass'field to use at the script.

Re: Replacing record from a field with a List

XanderBakker — Sun, 12 Dec 2021 00:41:38 GMT

I would start with moving setting to he beginning of the script. Like this:

def main():
    import arcpy

    # settings
    ws = r'C:\Teste_Auto_CLEIA\Auto_Classi\Dinamica_GDB.gdb'
    wildcard1, index1 = "S_pol_Din*", 0
    wildcard2, index2 = "pol*", 1
    fld_name = 'D2clust200m'
    name_from, name_to = 19, 36
    replace_text = "test"

    arcpy.env.workspace = ws

    try:
        fc1 = arcpy.ListFeatureClasses(wildcard1)[index1]
        print ("fc1: {}".format(fc1))

        fc2 = arcpy.ListFeatureClasses(wildcard2)[index2]
        print ("fc2: {}".format(fc2))

        fc_name = fc2[name_from: name_to]
        print ("fc_name: {}".format(fc_name))

        # update cursor
        with arcpy.da.UpdateCursor(fc1, (fld_name)) as curs:
            for row in curs:
                if row[0] is not None:
                    row[0] = row[0].replace(fc_name, replace_text)
                    curs.updateRow(row)

        print("Randy's try")

    except Exception as e:
        print(e)

if __name__ == '__main__':
    main()‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

In case you have multiple geodatabases that require the same treatment, you can create a loop to "walk" through multiple folders and subfolders and apply the process to every fgdb it finds.