Quick & Dirty python: Converting a text file to audio (.wav)

This is a bit of a tangent but for some crazy reason, I wanted to convert some text to audio so I could listen to it while I drive. A quick Google search left me without any freeware that could handle the 53 page document–there are some cool websites that do text to mp3 like vozme and YAKiToMe! but they didn’t convert the whole document. I then found pyTTS, a python package that serves as a wrapper to the Microsoft Speech API (SAPI) , which has been in version 5 since 2000. But I didn’t easily find a version of pyTTS for python 2.6. So I decided to see if I could roll my own.

As it turns out, getting python to talk using SAPI is relatively easy. Reading a plain text file can be done in a few lines.

from comtypes.client import CreateObject

infile = "c:/temp/text.txt"

engine = CreateObject("SAPI.SpVoice")

f = open(infile, 'r')
theText = f.read()


And it wasn’t that much more to have it write out a .wav file:

from comtypes.client import CreateObject

engine = CreateObject("SAPI.SpVoice")
stream = CreateObject("SAPI.SpFileStream")

infile = "c:/temp/text.txt"
outfile = "c:/temp/text4.wav"
stream.Open(outfile, SpeechLib.SSFMCreateForWrite)
engine.AudioOutputStream = stream

f = open(infile, 'r')
theText = f.read()



And with that chunk of code, I was able to convert my 54 page document into a 4 hour long .wav file (over 600 MB) that I used another software package to convert to .mp3 (200 MB). The voice is a bit robotic but not too bad, I just hope the content that I converted (a database specification standard) doesn’t put me to sleep while I drive.

Quick & Dirty arcpy: Autopan ArcMap using arcpy

Question: How do I get ArcMap to automatically pan through an area.

As I mentioned in a previous post, I recently had the need to have ArcMap automatically pan through a project area. My first attempt was to print a series of data-driven pages (using a fishnet polygon layer as the index) this but that did not accomplish what I needed so I switched to arcpy, which made the task simple enough. Nothing special or tricky about this code, but just did not find it anywhere else.

The one thing to note is that I have a 1 second pause between pans–this was to allow image tiles to download. You will need to adjust the delay to meet your needs. The toolbox and code can also be downloaded.

import sys,arcpy,datetime
inLayer = sys.argv[1]

def printit(inMessage):
    print inMessage

mxd = arcpy.mapping.MapDocument("CURRENT")

arcpy.MakeFeatureLayer_management(inLayer, "indexLayer")

df = arcpy.mapping.ListDataFrames(mxd)[0]
newExtent = df.extent

iCount = 0
iTotal = (arcpy.GetCount_management("indexLayer").getOutput(0))

for row in cur:
    thisPoly = row.getValue("Shape")
    newExtent.XMin, newExtent.YMin = thisPoly.extent.XMin, thisPoly.extent.YMin
    newExtent.XMax, newExtent.YMax = thisPoly.extent.XMax, thisPoly.extent.YMax
    df.extent = newExtent
    printit("Panned to feature {0} of {1}".format(iCount,iTotal))

del row
del cur

ArcMap Field Calculator: Identifying Unique Cases, Multiple Fields

You may have noticed that this post–ArcMap Field Calculator: Identifying Unique Cases, Single Field–specifies “Single Field”. Yes, that was my version of a cliff-hanger post.

The basic structure I listed in that post can be expanded on to satisfy your needs. The example in my earlier post was case sensitive for example, you could modify it so it treats “a” the same as “A”.

Today’s example groups records into different cases based off the values of two fields, !county_c! and !feature! and required only minor modifications.

The calling line was modified from:




to accommodate passing both values.

The function definition likewise was modified to accept two values, this:

def returnCase(inValue1):


def returnCase(inValue1, inValue2)

And this line was added, creating a list from the two values passed in:

inValue = [inValue1, inValue2]


(Note: The same results could have be achieved by using the original function by creating the list in the calling statement:  returnCase([!county_c!,!feature!] )


caseList = [ ]

def returnCase(inValue1, inValue2):
   inValue = [inValue1, inValue2]
   global caseList

   if not inValue in caseList:

   return caseList.index(inValue)

ArcMap Field Calculator: Text to Double

Received a request yesterday asking how to use the ArcMap Calculator to copy values from a Text field to a Double field using python syntax.  As any good blogger would do, I immediately thought, “Awesome! Someone’s question is the perfect topic for a new blog post”.

The python parser is actually pretty good at casting values on the fly so if the values in your text field (!Day! in my example) are valid values that can be converted to a Double value, it is as simple as just setting the formula to be the text field. In my example case, I wanted to copy the value from !Day! to !DecDay! so I set the formula to be DecDay = !Day!.

That should work fine if you have clean values in your text field. In the example above, you might notice I had a selected set of 3 records that all had numeric values in the !Day! field. When I included the fourth row, which does not have a numeric value in the text field, I get this error message (“There was a failure during processing, check the Geoprocessing Results window for details.” when I use the same formula. Time to add in an error exception.

For more advanced logic, the Field Calculator dialog allows you to use a python function if you check on the “Show Codeblock” option.  In the “Pre-Logic Script Code” area (Seriously, who at ESRI came up with that name?) I entered the following function. If the value in my text field (!Day!) can be cast to a number of type float, that value is returned. If the cast is unsuccessful (IE the value in !Day! is not a number), then I return -99.

def toNum(inValue):
      outValue = float(inValue)
      return outValue
      return -99

Then in the formula portion of the dialog, I call the function, passing the value in the !Day! field: DecDay = toNum(!Day!).

Now, if you would prefer not to set all the records with non-numeric values to be -99 or other error value, not return anything. To do this, I replaced the “return -99” in the original function with a filler line (“doNothing = 4”) since the try block needs an non-empty except clause.

def toNum(inValue):
      outValue = float(inValue)
      return outValue
      doNothing = 4

And that should leave the values in the double field unscathed in your records with non-numeric values in the text field.

Shameless Plug: Check out my other blog posts on using ArcMap’s Field Calculator to calculate geometry and converting a date value to an 8 digit numeric value.

Quicker & Cleaner python recursive folder search

As contributor of the day, Jason Scheirer, pointed out, python has a simple, direct way to browse through the subdirectories of a directory–os.walk

Here is a bare-bones example of using it to print out the subdirectories in a path. The files variable of the 3-tuple is a list of files similar to the dirs variable that I loop through.

Thanks Jason for pointing out something I missed.

import os

theDir = 'c:/temp/'

for root, dirs, files in os.walk(theDir,True,None):
    for idir in dirs:
        print "     directory:   {0}/{1}".format(root,idir)

Quick & Dirty python recursive folder search

Someone asked how to have python recursively search a folder structure. There may be a better way but this is how I typically do it–it basically starts with one directory and loops through the contents compiling a list of sub-directories as it goes through the contents.


import glob, os

theDir = 'c:/temp/'
theDirList = []

while len(theDirList) > 0:
    newDirList = []
    for iDir in theDirList:
        print iDir
        for iFile in glob.glob(iDir+"/*"):
            if (os.path.isdir(iFile)):

    theDirList = newDirList

ArcMap Field Calculator: ArcPy Date to Decimal Function

One of the standards in our databases is to store dates as 8-digit integer values in the format of yyyymmdd. This requires us to occasionally convert values from date fields into this format.

We can do this in the ArcMap Field Calculator using this arcpy function:

def datetodouble(inNum):
     splitList = str(inNum).split("/")
     return  splitList [2]  +("0"+ splitList [0])[-2:]  +("0"+ splitList [1])[-2:]

ArcMap Field Calculator: Create a Unique ID

One of the common functions I have to do is assign each record in a feature class with a unique identifier–normally just a sequential number from 1 to N.  In ArcView 3.x, the formula was simply “rec + 1” if I wanted to start with the number 1.

In ArcGIS, the process got a little more complex–you had to write a little VBA in Field Calculator as described by ESRI.

While this option still exists in ArcGIS 10, I believe it will disappear when 10.1 comes out and VBA support is completely eliminated.  But it is doable using Python which will continue to be supported.

Googling around, I did not find an exact answer but Dave Verbyla, Professor of GIS/Remote Sensing at the University of Alaska has a posted some samples that served as a good starting point.

In the Pre-Logic Script Code box, I declare a variable (counter) and a function. Then in the formula, I call the function.

counter = 0
def uniqueID():
  global counter
  counter += 1
  return counter

While composing this post, I actually wanted a concatenated value; “OC” plus an 8 character numeric sequential number starting at OC00000001 so the actual code is shown below:

Debugging a Python Scheduled Task

I have been working on a python script that I want (NEED) to run as a scheduled task on a remote machine.  I got to the point that the script did exactly what I needed when I was interactively running it in a Windows session but had problems when running it as a scheduled task.  The debugging process was cumbersome–make a change, schedule a task to run it, log out of the machine, and wait.  The log back in and repeat the process.

That got old.

So I wrote a script  (tester.py) that calls any other python scripts in the same directory that (1) start with “test_” and (2) there is not a corresponding file with the same base name and “.start” extension.  It would launch “test_BaBing.py” as long as there is not a “test_BaBing.start” in the same directory.  Tester.py continued to run, looping every 60 seconds, until tester.stop exists.

This made the process easier because I could work on my local machine, editing the problematic script, saving changes and within 60 seconds it would be launched on the remote machine.  I could view the results, make additional edits, delete the .start file and it would launch again within 60 seconds.

Within a couple minutes I was able to determine the problem (path related) and fix it.

Happy programmer.

<disclaimer>I would recommend using this only while debugging a script–routinely running it could be a security risk since someone could copy a destructive python script into the directory and this would run it.</disclaimer>

Download: tester.py

import sys, string, os
import glob
import datetime, shutil
import time, inspect
import getpass

totalstarttime = datetime.datetime.now()

dateString = datetime.date.today().strftime("%Y%m%d_")+datetime.datetime.now().strftime("%H%M%S") #datetime.date.today().strftime("%Y%m%d")
debugfile = inspect.getfile(inspect.currentframe()).replace(".py","_"+dateString+"_Debug.txt")
stopfile = inspect.getfile(inspect.currentframe()).replace(".py",".stop")
newdebugfile = False

codeDir = os.path.dirname(inspect.getfile(inspect.currentframe())).replace("\","/")

def printit(inText):
    global newdebugfile

    print inText

    if os.path.exists(debugfile):
        if (newdebugfile == False):
            tmpfile = open(debugfile,"w")
            newdebugfile = True
            tmpfile = open(debugfile,"a")
        tmpfile = open(debugfile,"w")

    newdebugfile = True

stopFileExists = False
printit("Code Directory: "+codeDir)
printit("Starting at: "+datetime.date.today().strftime("%Y-%m-%d_")+datetime.datetime.now().strftime("%H:%M:%S"))
printit("Stopfile : "+stopfile+"/n")
while (stopFileExists == False):
    for iFile in glob.glob(codeDir+"/test_*.py"):

        thisStartfile = iFile.replace(".py",".start")

        if not (os.path.exists(thisStartfile)):
            printit ("Launching: "+iFile)
            iTmpfile = open(thisStartfile,"w")
            os.system("Start "+iFile)

    if (os.path.exists(stopfile)):
        stopFileExists = True

    printit("nEnd of Loop: "+datetime.date.today().strftime("%Y-%m-%d_")+datetime.datetime.now().strftime("%H:%M:%S")+"n")    


Checking to see if a Field Index Exists Using Arcpy (ArGIS 10.0) redux

I’ve previously posted python code to check if a field index exists for both ArcGIs 9.3 and ArcGIS 10.0.

Recently I have been working on a process that was using this code but it was not working because it looks for an index with a specific name.  It was not working in this case because the name of the indexes was getting incremented as they were being created.  For example, I was building an index on the table C5ST, field RelateId ([C5IX].[Relateid]) named I_C5IX_RelateId.  That worked fine until we switched our process so now we keep multiple versions of some tables, each with a date-based suffix.

We now have tables name C5St_20110625 and C5St_20110626–the Index-name scheme, however was still creating I_C5IX_RelateId and it worked great on the first one.  But when it created the second one, even on a different table, it was automatically name I_C5IX_RelateId_2 even though the name I_C5IX_RelateId was used when trying to create the index.

Before generating relates, our code checks to see if the key fields are indexed, and if they are not, builds  an index.  Because of the naming situation, multiple, duplicate indexes were being created.  Probably not too harmful but it is a little messy.

So I re-wrote the code so that you pass the function the table name and field name that you want to check and it checks to see if there is an index existing for that field and return a Boolean.  The one little wrinkle I put in is to account for indexes that span multiple fields–the ” if (iIndex.fields[0].Name.upper() == fieldname.upper()):” statement is checking the index to see if it is on a single field or multiple fields.


def fieldHasIndex(tablename,fieldname):
if not arcpy.Exists(tablename):
return False

tabledescription = arcpy.Describe(tablename)

for iIndex in tabledescription.indexes:
if (len(iIndex.fields)==1):
if (iIndex.fields[0].Name.upper() == fieldname.upper()):
return True

return False