[SOLVED] How to overwrite text in text file

[redfield]

Hi guys,

can't get this to work. What I have is a text file, containing data like this:

2021-06-0182.83
2021-07-0184.45

What I want is to replace the number values (second column) with new ones, e. g. 82.83 with 79.98. But what I get is:

2021-06-0182.83
2021-07-0184.45
2021-07-0179.98

2021-08-0182.02

2021-09-0178.95

So the new values are appended and I even get empty rows in between . This is my code:

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 put specialFolderPath("resources") & "/" & "test.txt" into vPath
   open file specialFolderPath("resources") & "/" & "test.txt" for update
   read from file specialFolderPath("resources") & "/" & "test.txt" until EOF
 
   repeat for each word i in it
      if i contains "." then
         put theNewValue into n
         replace i with n in it
      end if
   end repeat
   
   write it to file specialFolderPath("resources") & "/" & "test.txt"
   close file specialFolderPath("resources") & "/" & "test.txt"

Help appreciated

[dunbarx]

Hi.

I assume you are doing all the massaging in LC before you write to the external file. So if you have your data in a variable "yourData":

2021-06-01 82.83
2021-07-01 84.45

How is the "second column" delimited from the first? A tab character between them? If so, did you:

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set the itemDel to tab
  get yourData
  put "79.98" into item 2 of line 1 of it

??

Craig

[dunbarx]

Hi again.

If you read your handler, you can see that for someone like me, I have little knowledge of how it works. I do not see the variable "theNewValue", for example. I do see that you are selecting lines that contain a period, but it seems so far that all lines do.

That is why I asked what the delimiter is. And the fact that you are getting empty rows is telling. Anyway, I bet that there is a simple solution, and you will get this going soon.

Little things, like you do not need to use the extra line that introduces the "n". You can just lose that. Just

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  replace i with theNewValue in it

This begs the issue whether the structure itself is sound.

Craig

[redfield]

Thanks Craig, for trying to understand my issue. The text file is actually created and filled by a Python script. The delimiter between the two "columns" are four spaces. The code now looks like this:

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put specialFolderPath("resources") & "/" & "test.txt" into vPath
open file vPath for update
read from file vPath until EOF

set the itemDel to tab

repeat for each line l in it
      answer word 2 of l
      put 100.0 into word 2 of l in it
end repeat
  
write it to file specialFolderPath("resources") & "/" & "test.txt"
close file specialFolderPath("resources") & "/" & "test.txt"

In the loop the "answer" is as expected. But trying to put 100.0 into word 2 throws an error: "can't find handler) near "in",".
I am puzzled...

[Klaus]

Hi redfield,

two big issues!

1. Only use IT when neccessary and as little as possible, IT wil change when you least expect IT!
Put IT immediately into a variable and work with that variable!

2. "repeat for each..." is READ-ONLY!
Means the container will not change or may show unexpected results as you have seen with your first script!
Create/fill a new variable with a "repeat for each..." loop lile this:

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...
put specialFolderPath("resources") & "/test.txt" into vPath
## open file vPath for update
## read from file vPath until EOF
   
## I always use the URL one-liner!
put url("file:" & vPath) into tText
   
set the itemDel to tab  
repeat for each line l in tText
   ## answer word 2 of l

   ## Use ITEM, since you have set the itemdelimiter above!
   put 100.0 into item 2 of l
   ## put 100.0 into word 2 of l
   put l & CR after tNewText
end repeat
   
## Get rid of trailing CR
delete char -1 of tNewText

## URL one-liner:
put tNewText into url("file:" & vPath)

## write it to file specialFolderPath("resources") & "/" & "test.txt"
## close file specialFolderPath("resources") & "/" & "test.txt"
...

Best

Klaus

[dunbarx]

OK.

Takes just a little practice to get going. One thing about the english-like syntax of LC is that new users believe they can just "talk" when building their code. They can, but there is still a strict syntax that you need to get used to.

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repeat for each line l in it
    ...
      put 100.0 into word 2 of l in it
end repeat

Cant do this. You can put 100.0 into word 2 of l, or you can put it into word 2 of it, but not into the pair of those two variables.

Your itemDelimiter needs to be what separates the two portions of each line, in your case, four spaces. So:

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set the itemDelimiter to "    " --(four spaces)

I suspect this will still need tweaking, but that is what this forum is for.

Craig

[redfield]

1. Only use IT when neccessary and as little as possible, IT wil change when you least expect IT!
Put IT immediately into a variable and work with that variable!

Okay will try to remember.

2. "repeat for each..." is READ-ONLY!

Wow... good to know!

Your itemDelimiter needs to be what separates the two portions of each line, in your case, four spaces. So:

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set the itemDelimiter to "    " --(four spaces)

Thanks, my code works well now, although I'm working with "word" instead of "item", which seems to be sufficient in this case, therefore I don't even need to use an itemdelimiter.

[Cairoo]

I'm not sure if it's really what you wanted, but the code seems to replace EVERY number in the second column with the same new number.
If that's what you wanted, then good. But if you wanted to replace a particular number like what your original post seemed to suggest, you may have to make some additional changes.

Gerrie