topic Re: Error using SearchCursor to export values to text file in Python Questions

Error using SearchCursor to export values to text file

EstherOlson-Murphy — Sun, 12 Dec 2021 16:35:31 GMT

I have created a very basic script (with the help of others) that uses a searchCursor to pull data from a feature class and, in theory, add that data to a text file.
I think I almost have it but I am still getting a few errors that I cannot figure out (I am completely new to python and am at a complete loss now).

The first error I get is as follows:
Traceback (most recent call last):
File "G:\Olson-Murphy_Week10\Scripts\MaterialSearch2.py", line 10, in <module>
Qry = "Material = " + '%s' %materialType
NameError: name 'materialType' is not defined

Failed to execute (MaterialReport).

By removing "%materialType" from the script i get this error to go away but then I am faced with another:

Traceback (most recent call last):
File "G:\Olson-Murphy_Week10\Scripts\MaterialSearch2.py", line 14, in <module>
MaterialSearch = arcpy.SearchCursor(fc,Qry, fields = "Material;Diameter;System")
File "c:\program files\arcgis\desktop10.1\arcpy\arcpy\__init__.py", line 1133, in SearchCursor
return gp.searchCursor(dataset, where_clause, spatial_reference, fields, sort_fields)
File "c:\program files\arcgis\desktop10.1\arcpy\arcpy\geoprocessing\_base.py", line 359, in searchCursor
self._gp.SearchCursor(*gp_fixargs(args, True)))
RuntimeError: ERROR 999999: Error executing function.

Failed to execute (MaterialReport).

My code can be found below. Anyone have any suggestions? (this code someone else did say worked on their machine so I am at a total loss)

import arcpy
# Set workspace
arcpy.env.workspace = r"G:\Olson-Murphy_Week10\SouthFloridaNaturalGas.gdb"


#Estabslish input feature class
fc = r"G:\Olson-Murphy_Week10\SouthFloridaNaturalGas.gdb\Mains"

# Establish materials search for tool
Qry = "Material = " + '%s' %materialType


# Create cursor to search gas mains by material
MaterialSearch = arcpy.SearchCursor(fc,Qry, fields = "Material;Diameter;System")

#Define output
outReport = arcpy.GetParameterAsText(1)

#Open the report text file in write mode
file = open (outReport, "w")

#Add Header lines to report text file
file.write("Mains found in this report include:\n")
file.write("Material:" + Qry + "\n")

#Results of SearchCursor
for row in MaterialSearch:
    rptMat = str(row.getValue("Material"))
    rptDiam = str(row.getValue("Diameter"))
    rptSys = str(row.getValue("System"))

    file.write(rptMat + " " + rptDiam + " " + rptSys + "\n")

del MaterialSearch, row

Re: Error using SearchCursor to export values to text file

Zeke — Fri, 13 Jun 2014 16:56:42 GMT

The first error message is telling you what's wrong. You trying to use a variable materialType, but haven't defined it. You first need a statement like materialType = 'plastic'. I'm also not sure you should have the % sign right next to the variable name - % materialType instead of %materialType. Maybe that's ok.

You may want to consider the more recent method of formatting strings:
Qry = "Material = {0}".format(materialType)

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Fri, 13 Jun 2014 17:07:42 GMT

The first error message is telling you what's wrong. You trying to use a variable materialType, but haven't defined it. You first need a statement like materialType = 'plastic'. I'm also not sure you should have the % sign right next to the variable name - % materialType instead of %materialType. Maybe that's ok.

You may want to consider the more recent method of formatting strings:
Qry = "Material = {0}".format(materialType)

Thank you for the other option of formatting. I think i like that better!

The way I have to took working I have it so you select the material type you want, its not something I want hard-coded into the scripit. That is what I am trying to to do with that bit of script.

With your formatting string I updated it so I think it should allow me to set the variable in the tool

Qry = "Material = {0}".format(arcpy.GetParameterAsText(0))

but I still get that second error posted above. Any ideas on what that one is? (I have been looking for this answer for a few days so any ideas would be greatly appreciated!)

Thank you!!!

Re: Error using SearchCursor to export values to text file

IanMurray — Sat, 11 Dec 2021 23:07:05 GMT

Hi Esther

Out of curiousity are what version of ArcGIS are you on? If you are on 10.1 or higher I would highly recommend using the arcpy.da.SearchCursor, since they are faster and the inputs are a little easier to use.

When using the old style cursors, the fields are the 4th parameter, not the third. so you would need a placeholder string between the query and your fields.

Secondly, the issue is your made your field parameter fields = "Material;Diameter;System"

This is likely what is causing it to crash, I would either declare the fields to a variable called fields before the cursor or just hard code the fields names in the cursor. Its looking for a string value, whereas you are making a variable there.

arcpy.SearchCursor(fc,Qry, "",  "Material; Diameter; System")

alternatively:

fields = "Material; Diameter; System"
arcpy.SearchCursor(fc,Qry, "",  fields)

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Fri, 13 Jun 2014 17:41:35 GMT

Ian,
Thank you for this information. Since I am using 10.1 I will have to look at acrpy.da.SeachCursor to see if that makes more sense to me. Unfortunately this is school assignment, due Sunday AM so I don't have much time to figure it out (plus, sadly, I have already been looking at this for a week!)

Also, than you for the alternatives for seachCursor in terms of how I was identifying the fields to. Unfortunately, after trying both yours suggestions I still got the same error.

Thank you again for help and any other suggestions!
Esther

Re: Error using SearchCursor to export values to text file

Zeke — Fri, 13 Jun 2014 18:08:24 GMT

Try printing Qry right after you set it to make sure it has the value you want. Maybe print other values as well.

For Get ParameterByText to work, you need to have made the script a tool, or run it from the command line with arguments. I recommend hard coding some values in for testing. Once it works there, you can switch to parameters.

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Sat, 11 Dec 2021 23:07:08 GMT

Try printing Qry right after you set it to make sure it has the value you want. Maybe print other values as well.

For Get ParameterByText to work, you need to have made the script a tool, or run it from the command line with arguments. I recommend hard coding some values in for testing. Once it works there, you can switch to parameters.

Thank you for reminding me to do this. I have been testing it as a tool (since that is my ultimate goal) but hard coding it is a good idea so I tried that, but now I am getting a syntax error that I cannot figure out. Here is the 'new' code.... syntax Error is associated with #Establish material search for tool: Qry is invalid syntax.


import arcpy
# Set workspace
arcpy.env.workspace = r"G:\Olson-Murphy_Week10\SouthFloridaNaturalGas.gdb"


#Estabslish input feature class
fc = r"G:\Olson-Murphy_Week10\SouthFloridaNaturalGas.gdb\Mains"

# Establish Class fields
Field = ["Material", "Diameter", "System]"

# Establish materials search for tool
Qry ="Material = Plastic"

# Establish Class fields
Field = ["Material", "Diameter", "System]"

#Define output
outReport = arcpy.GetParameterAsText(1)

#Open the report text file in write mode
file = open (outReport, "w")

#Add Header lines to report text file
file.write("Mains found in this report include:\n")
file.write("Material:" + Qry + "\n")

# Create cursor to search gas mains by material
arcpy.da.SearchCursor(fc,Qry, fields) as Qry:
    for row in Qry:
    rptMat = str(row.getValue("Material"))
    rptDiam = str(row.getValue("Diameter"))
    rptSys = str(row.getValue("System"))

    file.write(rptMat + " " + rptDiam + " " + rptSys + "\n")

del Qry, row

Re: Error using SearchCursor to export values to text file

IanMurray — Sat, 11 Dec 2021 23:07:10 GMT

Query expressions can be a bit annoying to put into a python script, especially if you have to store them as a string.

try


Qry ="'Material' = \"Plastic\""

Check this link for more help on building query expressions

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Sat, 11 Dec 2021 23:07:13 GMT

try


Qry ="'Material' = \"Plastic\""

Tried this but still have the same syntax error

exceptions.SyntaxError:invalid syntax (line 13, offset 3) 'Qry ="'Material' = \"Plastic\""'

After all the time I have spent looking at this I have a feeling its a mix of mass confusion on my part and total rookie mistakes.
I have managed to get similar codes to work not as tools, but simply printing the results, but for some reason this one is really fighting me!

Thank you for all the help. As you can tell I'm a little lost and frustrated!

Re: Error using SearchCursor to export values to text file

IanMurray — Sat, 11 Dec 2021 23:07:15 GMT

I see you switched over to arcpy.da.cursor, and that is part of what is causing the new issue.

arcpy.da.SearchCursor(fc,Qry, fields) as Qry:

first parameters is your fc, second parameter is fields (as a list, which you did, great job!), third parameter is the where clause

so it should be


with arcpy.da.SearchCursor(fc, fields, Qry) as cursor:  """(you don't want to use Qry, since that variable is already declared) """
  for row in cursor:
    rptMat = str(row.getValue("Material"))
    rptDiam = str(row.getValue("Diameter"))
    rptSys = str(row.getValue("System"))

I just finished my first python class last semester, and it frustrated a good half of the class alot, especially since almost none of us had a CS background.

Edit: Greg I noticed that extra quotation as well, but I figured she had already gotten past that syntax error, with the error code she was throwing

Re: Error using SearchCursor to export values to text file

Zeke — Fri, 13 Jun 2014 19:18:17 GMT

Ian fixed it, but also notice that when you set the SearchCursor, you forgot the with keyword.

Not sure why you set Field twice, but no harm done. Except you have the last quotation mark outside the closing list bracket.

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Fri, 13 Jun 2014 19:25:14 GMT

Thank you Ian!

Things seem to be working better now (and I saw the missing keyword too 🙂 )... and I figured out the syntax error as well (brackets in the wrong place!).

Now, though, another error! (shocking 😉 )

This time I am getting with my SearchCursor.

"RuntimeError: cannot open 'G:\Olson-Murphy_Week10\SouthFloridaNaturalGas.gdb\Mains"

I have copied this location out of arcCatalog so I know its not location issue. I also removed the '-' and '_' and re-pathed everything to make sure that was not the issue.... I'm going to keep fighting with it but any more ideas?

I hope all you pros are having fun picking apart this easy little script 🙂

Re: Error using SearchCursor to export values to text file

IanMurray — Fri, 13 Jun 2014 19:35:16 GMT

Not sure this is it, but in the error code it threw, it shows a single quote starting your file location and no single quote ending it.

Also, the file is just a fc in the gdb, not within a feature dataset or anything, if it is, you need to add the feature dataset to your file path. You shouldn't need to hard code the file path, since you set your environment, it will automatically check that location for the file, so you could do fc = "Mains", though for the sake of this particular script I'd leave it alone til it is working.

Make sure you don't have the file Mains open in ArcCatalog or ArcGIS, it will have a lock on it making you unable to access it with the cursor(I think).

Edit: Haha, yes always lots of error codes. I always get tons of them on scripts I write, but it feels to much better by the time works right. For future reference, I'd write small parts of code at a time, debugging each section as I go. Once you get one section working, move to the next, it makes it easier to handle errors, and you get small victories as you go, instead of a pile of possible errors at the end.

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Fri, 13 Jun 2014 23:09:04 GMT

Thank you everyone for the help!
I wish I had time time (and skill) to do this in steps to make sure everything worked before moving on but, alas, I do not.
I am still getting the same RuntimeError: Cannot Open "Feature Class" and am unsure why. I have tried double quote, single quotes, full path, just the feature class name, and changed the capitalization still without any luck.

Below is what I am working with. If anyone is REALLY bored and wants data to play with let me know:) ... or if you just see some glaring errors.

At least I am ahead of where I was before.... now at least the header end up in the text time 🙂

Thanks again for all the help

import arcpy
# Set workspace
arcpy.env.workspace = r"E:\OlsonMurphyWeek10\SouthFloridaNaturalGas.gdb"

#Estabslish input feature class
fc = r"E:\OlsonMurphyWeek10\SouthFloridaNaturalGas.gdb\Mains"

# Establish Class fields
fields = ["Material", "Diameter", "System"]

# Establish materials search for tool
Qry ="'Material' = \"Plastic\""

#Define output
outReport = r"E:\OlsonMurphyWeek10\Outputs\Report.txt"

#Open the report text file in write mode
file = open (outReport, "w")

#Add Header lines to report text file
file.write("South FLorida Distrbution Mains:\n")
file.write("Material:" + Qry + "\n")

# Create cursor to search gas mains by material
with arcpy.da.SearchCursor(fc, fields, Qry) as cursor:
for row in cursor:
    rptMat = str(row.getValue("Material"))
    rptDiam = str(row.getValue("Diameter"))
    rptSys = str(row.getValue("System"))

    file.write(rptMat + " " + rptDiam + " " + rptSys + "\n")

del cursor, row

[\CODE]

Re: Error using SearchCursor to export values to text file

Zeke — Sat, 14 Jun 2014 00:56:50 GMT

How about you post your code and data (or a sample), and I'll try to look at it this weekend. Its Fathers day weekend, so can't promise your Sunday deadline, but will try if possible.

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Sat, 14 Jun 2014 01:00:44 GMT

How about you post your code and data (or a sample), and I'll try to look at it this weekend. Its Fathers day weekend, so can't promise your Sunday deadline, but will try if possible.

Thank you so much! that would be great.
Just make sure you don't miss out on Father's Day weekend... its an important one!!

I have attached a zip folder with my data and script. Its all dummy data I made up for the project so its very basic, and there isn't a lot of it 😉

Thanks Again
Esther

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Sat, 14 Jun 2014 23:27:30 GMT

I want to thank everyone again for all the help.
While I may not manage to get this script tool to work for this week's due date, I do hope to use it for a project I am doing for class as well as for work so I am still working at it.

That being said, does anyone know why I would get the error that my feature class cannot be opened? Would this be different than not being able to locate the feature class? As far as I can tell it is not locked and it not opened anywhere accept for in the MXD I am working with. So confused!

Thanks
Esther

Re: Error using SearchCursor to export values to text file

Zeke — Sat, 11 Dec 2021 23:07:18 GMT

Esther,

Sorry if this is too late for your deadline, had a busy weekend. I've tried several variations of the script below, which as far as I can see should work, but also getting the can't open error. I'm starting to think it's a problem because (at home) I'm on 10.2, but the data was created in 10.2.1 or 10.2.2, except I see it fine in ArcCatalog. Can't export it, though, so no help there.

What version of Arc are you using? Another possibility is that the gdb or data got corrupted somehow. Can you get a fresh copy? You did a good job setting it up as a tool, so kudos there.

edit: oh, also, wouldn't use 'Expression' with an upper case e, since that comes up as an existing word in intellisense.

import arcpy

fc = r"C:\Test\OlsonMurphyWeek10\SouthFloridaNaturalGas.gdb\Mains"
classField = "Material"
fields = ["Material", "Diameter", "System"]
expression = arcpy.AddFieldDelimiters(fc, classField) + " = 'Plastic'"

#Define output
##outReport = arcpy.GetParameterAsText(1)
outReport = r"C:\Test\Esther.txt"

#Open the report text file in write mode
with open(outReport, "w") as rptFile:
    #Add Header lines to report text file
    rptFile.write("Mains found in this report include:\n")
    rptFile.write(expression + "\n")
print fc
print fields
print expression
# Create cursor to search gas mains by material
with arcpy.da.SearchCursor(fc, fields, expression) as cursor:
    for row in cursor:
        rptMat = str(row.getValue("Material"))
        rptDiam = str(row.getValue("Diameter"))
        rptSys = str(row.getValue("System"))

        rptFile.write(rptMat + " " + rptDiam + " " + rptSys + "\n")

print "Done!"

Re: Error using SearchCursor to export values to text file

EstherOlson-Murphy — Tue, 17 Jun 2014 16:16:56 GMT

Thank you for taking another look at it. While it is a bit frustrating that it doesn't seem to be working i do feel a bit better that, perhaps, it is not me!

I will try to re-create the gdb. Unfortunately I created the data on my own and, stupidly, did not create a back up for it (oh retrospect!). If my new gdb doesn't work i can just recreated the data and try again. I would rather not but it really doesn't take too long to so and, if it means success, I'm game!

Thank you again for taking your time to take a look!
Esther