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I was looking at the writing to a text file using python/processing and noticed that there is something called: "createWriter". Is this the only way? I am used to using:
After several attempts at using "open", I couldn't get it to create the text file BUT, for some reason:
seems to work.
Here is my code :
f = open('text.txt', 'w')
If I have to use CreateWriter, I will, but I was wondering why the "r" works, but the "w" does not?
It is highly recommended to use Processing's API functions when dealing w/ files.
B/c they take into consideration the internal variable sketchPath, which is a String representing the folder our sketch is running from.
For ".txt" files, Processing's got loadStrings() & saveStrings():
They also have the added bonus of using the encoding UTF-8 btW. \m/
P.S.: When using Processing's save functions, such as saveStrings(), it is highly recommended to call the undocumented dataPath() passing the String filename: L-)
saveStrings( this.dataPath('text.txt'), stringArray )
This way, the file is saved inside sketch's subfolder "data/" instead of its sketchPath's root. :-bd
Ok, I tried that and it works thanks. I couldn't get saving txt files until you showed me that. Is there anything undocuments for csv files too?
Although absent in Python Mode's API reference: http://Py.Processing.org/reference/
B/c it uses the same Processing library as the main Java Mode, both loadTable() & saveTable() are available from within Python Mode:
So we can handle both ".csv" & ".tsv" files under Python Mode too. :>
I am trying this, but nothing gets printed to the console or otherwise. I did try to iterate through table.rows, but got an error saying there was no attribute for rows.
I am not verse on Java, so I am trying to parse through the links you gave me and figure it out, without much success...Thanks again for the help!
These are the documented methods for class Table:
B/c the devs haven't
@Overridethe Object::toString() method in class Table: :-B
printit, some hexadecimal gibberish is displayed. 8-X
In order to see its content, we do need to traverse the Table object.
For that, we can invoke the Table::rows() method: *-:)
Then use it in a
Something like this:
for tr in table.rows():B-)
Notice though that the iterator tr is of datatype TableRow now, and got instead these methods:
Ok, I am trying to figure out what you are saying here: 1) The "Tables method" in java has a method of creating tables with columns and rows. 2) I do not get any gibberish when I run the above code in my previous post. 3) The table rows() method gives me this error "nonetype" object has no attribute "rows". 4) I am using the:
for i in table.rows()when I get this error. 5) Are you saying that I have to create the spreadsheet using the table function, rather than being able to pull the info from a csv file?
For that specific case, you'd need to
importthe Table class.
None, nothing's gonna work!
Ok, thanks for the clarification, but when I go to import Table, it gives me an error saying there is "no module named Table". Tried the two below with capitalization and lower case:
@netrate -- okay, you seem to be confused about a couple things that are making it harder for you to find solutions.
You don't need to use "import" to access the built-in Processing API. You don't need to import PImage, PVector, Table etc. etc. -- those are built-in. Just use them. Edit: loadTable does not require import, directly creating a Table does, see below
There is already documentation for this -- both the reference, and examples!
Open up a Python mode sketch, then go to File > Examples. In the Python Examples window, navigate to Topics > Advanced Data > LoadSaveTable. Run the sketch
LoadSaveTable.pydeand click to interact. Look at the code. Look at the
data/data.csvfile in the sketch folder. Notice that every time you click, it saves the updated file to disk.
Ask more questions here if you still need more help with loading and saving CSV files after looking over this working example!
ty, I will look over this example. I appreciate the patience!
Not a problem -- here to help. Let us know how it goes!
Even though those 3 classes are builtins, Table isn't visible under Python Mode like the other 2 classes. @-)
So, in order to instantiate the class Table under Python Mode, we do need to import it 1st:
from processing.data import Table
Fortunately, at least loadTable() & saveTable(), which are methods from class PApplet, are already globally visible. >-)
Good point! Although most demo sketches don't import it -- because if you are instantiating your Table from the built-in loadTable then no import is needed:
Ok I think I am getting the read portion of it. I used the example you suggested and set up some columns and read the values in the rows that were associated with the fields.
name age john 34 bill 66
I am having some challenges with saving though. Right now I have added a new column called "car" and I am trying to add a integer of the year so it will look like: name age car john 34 2015 bill 66 2018
I was hoping to put the years in a list and draw from that, but I am getting an error when I do. It says list indices must be integers.
If I set the row.setInt to a single number like this:
It works but puts 2018 for both John and Bill's rows. I wanted just to read for a list and put them in the proper place using that list indexes. I am hoping it is something simple.
rowisn't an index integer -- it is a
TableRowobject, which is why you can call its
row.setInt()method. I don't think you can access a list item
car_year[TableRow]-- that doesn't make sense.
It seems like perhaps you want to loop with an index? Example tutorial on approaches:
Another way of approaching this kind of problem is list comprehension. Example tutorial:
So how would I go about writing new data in the CAR field so that is works with each new row adding a different car year for each person?