Read TextGrid labels into a Strings object in Praat - praat

Question

I am stuck trying to figure out how to read the strings from a textgrid which is open in the window but not saved to the hard disk as a raw text file. My goal is to manipulate the strings and save them later.
I want to do something like this but don't really understand how the syntax would work.
tG$ = selectObject: selected$("TextGrid")
stringID = Read Strings from tG
numberOfStrings = Get number of strings
for stringNumber from 0 to numberOfStrings
selectObject: stringID
line$ = Get string: stringNumber
...

Answer 1

You need to loop through the intervals in the TextGrid and use appendFileLine to output the labels to a text file. For example:
# Your need to select the TextGrid manually, and it has only one tier (tier number 1)
outputFile$ = "~/Desktop/output.txt"
writeFile: outputFile$, "" ; start from an empty .txt
numberOfIntervals = Get number of intervals: 1 ; (this is tier 1)
for interval to numberOfIntervals
label$ = Get label of interval: 1, interval
if label$ != "" ; (we just want non-empty intervals)
xmin = Get start time of interval: 1, interval
xmax = Get end time of interval: 1, interval
appendFileLine: outputFile$, "'label$''tab$''xmin''tab$''xmax'"
endif
endfor
This script will output a .txt file with tab delimited values: label, xmin, xmax. You can change the appendFileLine arguments to your needs (tab$ is a predefined variable, which is... a tab).

Answer 2

TextGrid labels are not directly translatable to a Strings object because, unlike a TextGrid, Strings objects do not have tiers. So you could have code that takes all of the labels of a specific tier in a TextGrid and pushes them into a Strings object.
0. Creating an empty Strings
The problem here is that Praat does not want you to populate Strings object yourself, so there is no Create empty Strings.... However, you can subvert one of the existing commands to do this:
Create Strings as tokens: ""
1. Pushing the labels to a Strings object
Now that we have an empty Strings to populate, we can get to work:
procedure labelsToStrings: .tier
.textgrid = selected("TextGrid")
# Make sure this works with interval and point tiers
.item$ = if do("Is interval tier...", .tier) then
... "interval" else "point" fi
# Make the empty Strings
.strings = Create Strings as tokens: ""
Rename: selected$("TextGrid")
# Fetch each label, and insert it to the Strings object
selectObject: .textgrid
.n = do("Get number of " + .item$ + "s...", .tier)
for .i to .n
selectObject: .textgrid
.label$ = do$("Get label of " + .item$ + "...", .tier, .i)
# I assume you don't care about empty labels?
if .label$ != ""
selectObject: .strings
Insert string: 0, .label$
endif
endfor
# Make sure the new object is selected
selectObject: .strings
endproc
2. Profit!
You can try it out:
synth = Create SpeechSynthesizer: "English", "default"
To Sound: "This is some text.", "yes"
sound = selected("Sound")
textgrid = selected("TextGrid")
selectObject: textgrid
#labelsToStrings: 4
removeObject: sound, synth
View & Edit
3. Bonus
If you are interested in getting all the labels in a more manageable package, you might also be interested in the Index specified labels... command from the tgutils plugin, which I also wrote. (I know: I'm amazing at naming things).
That one does something similar to this, but instead of using a Strings object, it dumps all the labels to a Table, as well as the timestamp of points, or the start and end of intervals. And you can also specify subsets of labels to consider using a literal match or a regular expression.
With it, you can re-write #labelsToStrings to look like this:
procedure labelsToStrings: .tier
.name$ = selected$("TextGrid")
runScript: preferencesDirectory$ + "/plugin_tgutils/scripts/" +
... "index_specified_labels.praat", .tier, ".+", "yes"
.table = selected("Table")
Create Strings as tokens: ""
Rename: .name$
for .i to Object_'.table'.nrow
.label$ = Object_'.table'$[.i, "label"]
Insert string: 0, .label$
endfor
removeObject: .table
endproc