# How do you sort a dataset?

**URL:** <https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090>\
**Category:** Ignition\
**Created:** [March 1, 2012, 8:37pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090 "2012-03-01T20:37:58Z")\
**Posts on this page:** 17\
**Page:** 1

<div class="post-metadata">

**Author:** ![TimE](https://avatars.discourse-cdn.com/v4/letter/t/ee59a6/32.png) [@TimE](https://forum.inductiveautomation.com/u/TimE)\
**Post date:** [March 1, 2012, 8:37pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/1 "2012-03-01T20:37:58Z")

</div>

I find myself stumped again! I have sorted lists before but I am at a loss as to why I cannot do this. The table I am trying to sort has three columns and about 50 rows.

`ds = event.source.parent.getComponent('Table').data
pyData = system.dataset.toPyDataSet(ds)
ds.sort()
`

This is the error …

[quote]Traceback (innermost last):  
File “event:actionPerformed”, line 3, in ?  
AttributeError: sort

```
at org.python.core.Py.AttributeError(Py.java)
at org.python.core.PyInstance.invoke(PyInstance.java)
at org.python.pycode._pyx150.f$0(<event:actionPerformed>:3)
at org.python.pycode._pyx150.call_function(<event:actionPerformed>)
at org.python.core.PyTableCode.call(PyTableCode.java)
at org.python.core.PyCode.call(PyCode.java)
at org.python.core.Py.runCode(Py.java)
at com.inductiveautomation.ignition.common.script.ScriptManager.runCode(ScriptManager.java:395)
at com.inductiveautomation.factorypmi.application.binding.action.ActionAdapter.runActions(ActionAdapter.java:139)
at com.inductiveautomation.factorypmi.application.binding.action.ActionAdapter.invoke(ActionAdapter.java:247)
at com.inductiveautomation.factorypmi.application.binding.action.RelayInvocationHandler.invoke(RelayInvocationHandler.java:55)
at $Proxy6.actionPerformed(Unknown Source)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

```

Ignition v7.3.1 (b496)  
Java: Sun Microsystems Inc. 1.6.0\_27  
[/quote]

What is the proper way to perform a sort?  
Thanks,

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [March 1, 2012, 9:33pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/2 "2012-03-01T21:33:05Z")

</div>

Yeah, DataSet doesn’t have a sort() method… looks like you need to sort it yourself. Will get back to you with a code snippet…

---

<div class="post-metadata">

**Author:** ![TimE](https://avatars.discourse-cdn.com/v4/letter/t/ee59a6/32.png) [@TimE](https://forum.inductiveautomation.com/u/TimE)\
**Post date:** [March 1, 2012, 9:36pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/3 "2012-03-01T21:36:17Z")

</div>

Correction to the original post. (I had tried every combination I could think of)

`ds = event.source.parent.getComponent('Table').data
pyData = system.dataset.toPyDataSet(ds)
pyData.sort()`

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [March 1, 2012, 10:30pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/4 "2012-03-01T22:30:47Z")

</div>

This is a bit ugly… we should really add a scripting function that will sort a DataSet.

```auto
headers = ["Column 1", "Column 2"]
data = [['z','foo'],['w','bar'],['a','baz']]
ds = system.dataset.toDataSet(headers, data)

def sortDataSet(ds, key_column = 0):
	# create headers
	headers = [ds.getColumnName(x) for x in range(ds.columnCount-1)]
	
	# create data
	import system
	py_ds = system.dataset.toPyDataSet(ds)
	rows = [py_ds[x] for x in range(len(py_ds))]
	rows.sort(lambda x,y,key=key_column: cmp(x[key], y[key]))
	data = [[row[x] for x in range(len(rows)-1)] for row in rows]
	
	return system.dataset.toDataSet(headers, data)

print sortDataSet(ds)
```

---

<div class="post-metadata">

**Author:** ![TimE](https://avatars.discourse-cdn.com/v4/letter/t/ee59a6/32.png) [@TimE](https://forum.inductiveautomation.com/u/TimE)\
**Post date:** [March 2, 2012, 8:21pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/5 "2012-03-02T20:21:35Z")

</div>

I copied your code and it worked in the playground but not when I entered it into my project.

`def sortData(ds, key_column = 2):
	import system
	headers = [ds.getColumnName(x) for x in range(ds.columnCount)]
	pyData = system.dataset.toPyDataSet(ds)
	rows = [pyData[x] for x in range(len(pyData))]
	rows.sort(lambda x,y,key=key_column: cmp(x[key], y[key]))
	data = [[row[x] for x in range(len(rows)-1)] for row in rows]
	return system.dataset.toDataSet(headers, data)
`

Line 366 is the 'data = ’ statement above.

[quote]Traceback (innermost last):  
File “event:actionPerformed”, line 37, in ?  
File “module:math”, line 366, in sortData  
IndexError: Column index 3 out of range.

```
at org.python.core.Py.IndexError(Py.java)
at com.inductiveautomation.ignition.common.script.builtin.DatasetUtilities$PyDataSet$PyRow. __getitem__ (DatasetUtilities.java:102)
at sun.reflect.GeneratedMethodAccessor97.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.python.core.PyReflectedFunction. __call__ (PyReflectedFunction.java)
at org.python.core.PyMethod. __call__ (PyMethod.java)
at org.python.core.PyObject. __call__ (PyObject.java)
at org.python.core.PyInstance.invoke(PyInstance.java)
at org.python.core.PyInstance. __getitem__ (PyInstance.java)
at org.python.pycode._pyx273.sortData$16(<module:math>:366)
at org.python.pycode._pyx273.call_function(<module:math>)
at org.python.core.PyTableCode.call(PyTableCode.java)
at org.python.core.PyTableCode.call(PyTableCode.java)
at org.python.core.PyTableCode.call(PyTableCode.java)
at org.python.core.PyFunction. __call__ (PyFunction.java)
at org.python.core.PyObject.invoke(PyObject.java)
at org.python.pycode._pyx272.f$0(<event:actionPerformed>:37)
at org.python.pycode._pyx272.call_function(<event:actionPerformed>)
at org.python.core.PyTableCode.call(PyTableCode.java)
at org.python.core.PyCode.call(PyCode.java)
at org.python.core.Py.runCode(Py.java)
at com.inductiveautomation.ignition.common.script.ScriptManager.runCode(ScriptManager.java:395)
at com.inductiveautomation.factorypmi.application.binding.action.ActionAdapter.runActions(ActionAdapter.java:139)
at com.inductiveautomation.factorypmi.application.binding.action.ActionAdapter.invoke(ActionAdapter.java:247)
at com.inductiveautomation.factorypmi.application.binding.action.RelayInvocationHandler.invoke(RelayInvocationHandler.java:55)
at $Proxy5.actionPerformed(Unknown Source)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

```

Ignition v7.3.1 (b496)  
Java: Sun Microsystems Inc. 1.6.0\_27  
[/quote]

I attached the data I am working with. I am trying to sort this so I can extract rows for the top 5 heights.  
Thanks,  
[data.txt](https://us1.discourse-cdn.com/inductiveautomation/original/1X/c41387e0eeb6eed310f9e5b8003d7202ffd017c4.txt) (2.76 KB)

---

<div class="post-metadata">

**Author:** ![Colby.Clegg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/colby.clegg/32/3282_2.png) [@Colby.Clegg](https://forum.inductiveautomation.com/u/Colby.Clegg)\
**Post date:** [March 2, 2012, 11:15pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/6 "2012-03-02T23:15:50Z")

</div>

I think there’s a problem in the script, which you seemed to catch in one place already, where the row count is being used instead of the column count.

I didn’t mock this up, but it looks like on that line you want to loop through all columns for all rows. Instead of “data = [[row[x] for x in range(len(rows)-1)] for row in rows]” I think you want:

```auto
data = [[row[x] for x in range(ds.columnCount)] for row in rows]
```

EDIT:  
Here is the final CORRECT version of this code.

[code]headers = [“Column 1”, “Column 2”]  
data = [[‘z’,‘foo’],[‘w’,‘bar’],[‘a’,‘baz’]]  
ds = system.dataset.toDataSet(headers, data)

def sortDataSet(ds, key\_column = 0):

# create headers

headers = [ds.getColumnName(x) for x in range(ds.columnCount)]

# create data

import system  
py\_ds = system.dataset.toPyDataSet(ds)  
rows = [py\_ds[x] for x in range(len(py\_ds))]  
rows.sort(lambda x,y,key=key\_column: cmp(x[key], y[key]))  
data = [[row[x] for x in range(ds.columnCount)] for row in rows]

return system.dataset.toDataSet(headers, data)

# this uses the Ignition dataset (not a pydataset) that was created in line 3

print sortDataSet(ds)[/code]

Regards,

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [March 27, 2012, 9:21pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/7 "2012-03-27T21:21:57Z")

</div>

Scripting and expression functions for sorting a dataset have been added for the 7.4 final release.

---

<div class="post-metadata">

**Author:** ![juan](https://avatars.discourse-cdn.com/v4/letter/j/a698b9/32.png) [@juan](https://forum.inductiveautomation.com/u/juan)\
**Post date:** [November 7, 2019, 4:29pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/8 "2019-11-07T16:29:47Z")

</div>

in 8.1 the sort method does not sort my dataset

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 7, 2019, 4:30pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/9 "2019-11-07T16:30:30Z")

</div>

Are you from the future? There is no version 8.1 🙂

Show us the code you’re using?

---

<div class="post-metadata">

**Author:** ![jacque\_trahan](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jacque_trahan/32/58886_2.png) [@jacque\_trahan](https://forum.inductiveautomation.com/u/jacque_trahan)\
**Post date:** [November 29, 2023, 5:11pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/10 "2023-11-29T17:11:13Z")

</div>

This works great, but I was curious.  
Is there a way to sort Alphabetically based on the headers? This sort, sorts, exactly as expect based on column index, but it would be amazingly to not have to make a custom script to sort the headers and instead use the ignition built in function. Just would like to make sure I am not missing this somewhere before I make my own function for it.

Docs on the Ignition function I am currently using:  
[system.dataset.sort](https://docs.inductiveautomation.com/display/DOC81/system.dataset.sort)

Code example:

```auto
	# function to build a dataSet dictionary to update our tagPath
	def buildDataSet(colHeader):
		"""
		♠ Get the headers/Values of a a CSV files to start building out the Dataset Values
		"""
		dataSet = {}
		for key, value in colHeader.items():
			if key not in ['TagPath', 'MeterPath']:
				dataSet[key] = value
		return dataSet

# *Read in a CSV file as a Dict here to get colHeader (left this out for this commit)*

dataSetToWrite = buildDataSet(colHeader)

# create the new dataset
updatedDataset = system.dataset.toDataSet(dataSetToWrite.keys(), [dataSetToWrite.values()])
# sort data set based on column index 0
sortedDataSet = system.dataset.sort(updatedDataset, 0,True)
# write to the current Row's Tagpath to OVERWRITE the old Dataset
system.tag.writeBlocking(tagPath, sortedDataSet)

```

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 29, 2023, 5:23pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/11 "2023-11-29T17:23:50Z")

</div>

> [@jacque\_trahan](#):
>
> Is there a way to sort Alphabetically based on the headers?

I don't know what you're asking here. Can you explain and provide an example?

---

<div class="post-metadata">

**Author:** ![jacque\_trahan](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jacque_trahan/32/58886_2.png) [@jacque\_trahan](https://forum.inductiveautomation.com/u/jacque_trahan)\
**Post date:** [November 29, 2023, 6:25pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/12 "2023-11-29T18:25:18Z")

</div>

Sure!  
When I write to the memory tag that has a data set the headers are random.  
Example:

> Headers: **C | D| E | A | B**

I would like them to be like this:

> Headers: **A | B | C | D | E**

I may not know which column index starts with, in the above example, "A". So, sorting by column index is a little difficult and would rather a dynamic way to just alphabetize the headers then write the data to the tag.

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [November 29, 2023, 6:28pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/13 "2023-11-29T18:28:01Z")

</div>

Okay, you'll have to do that yourself. The built-in sort function is for sorting the rows, not sorting the columns.

---

<div class="post-metadata">

**Author:** ![Felipe\_CRM](https://avatars.discourse-cdn.com/v4/letter/f/dfb087/32.png) [@Felipe\_CRM](https://forum.inductiveautomation.com/u/Felipe_CRM)\
**Post date:** [November 29, 2023, 6:31pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/14 "2023-11-29T18:31:19Z")

</div>

```auto
sorted_headers = dataset.getColumnNames()
sorted_headers.sort()
column_sorted_dataset = system.dataset.filterColumns(dataset, sorted_headers)

```

should do what you want.

EDIT: forgot python sorts in place.

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [November 29, 2023, 6:34pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/15 "2023-11-29T18:34:08Z")

</div>

You can do that with the (somewhat confusingly named) `system.dataset.filterColumns` function efficiently.

Well, @Felipe_CRM beat me to it but `sorted` is also nice to make this a one-liner 🙂

```auto
ds = system.dataset.toDataSet(["bat", "rat", "cat", "hat"], [])

def sortColumns(ds):
	return system.dataset.filterColumns(ds, sorted(ds.columnNames))

	
print ds.columnNames
print sortColumns(ds).columnNames

```

---

<div class="post-metadata">

**Author:** ![Felipe\_CRM](https://avatars.discourse-cdn.com/v4/letter/f/dfb087/32.png) [@Felipe\_CRM](https://forum.inductiveautomation.com/u/Felipe_CRM)\
**Post date:** [November 29, 2023, 6:35pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/16 "2023-11-29T18:35:04Z")

</div>

Well, I just learned something today with the `sorted()` function, very nice!

---

<div class="post-metadata">

**Author:** ![pascal.fragnoud](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pascal.fragnoud/32/24728_2.png) [@pascal.fragnoud](https://forum.inductiveautomation.com/u/pascal.fragnoud)\
**Post date:** [November 29, 2023, 6:47pm UTC](https://forum.inductiveautomation.com/t/how-do-you-sort-a-dataset/4090/17 "2023-11-29T18:47:12Z")

</div>

can't try it, but something like this should do it:

```python
headers = sorted(ds.columnNames)
ds = system.dataset.filterColumns(ds, headers)

```

edit:  
huh, I was late to the party